Exhibit 3.6

                          CERTIFICATE OF INCORPORATION

                                       OF

                       SOUTHWESTERN FINANCIAL CORPORATION

                                    ---000---

          FIRST. The name of the corporation is SOUTHWESTERN FINANCIAL
CORPORATION.

          SECOND. Its principal office in the State of Delaware is located at
No. 100 West Tenth Street, in the City of Wilmington, County of New Castle. The
name and address of its resident agent is The Corporation Trust Company, No. 100
West Tenth Street, Wilmington 99, Delaware.

          THIRD. The nature of the business, or objects or purposes to be
transacted, promoted or carried on are:

          To design, manufacture, construct, erect, assemble, purchase, lease,
     rent, import, or otherwise acquire, handle, own, use, store, reconstruct,
     remodel, repair, mortgage or otherwise encumber, sell, export, assign,
     distribute or otherwise dispose of and in any manner to deal and trade in
     and with machinery, machines, tools, mechanical apparatus, tank cars,
     railroad cars, storage tanks, automobile bodies, chassis, tops, internal
     combustion engines and motors of every kind and description, any and all
     parts, fittings, appliances, supplies, novelties, appurtenances and
     accessories for railroad cars, automobiles, trucks, tractors, omnibuses and
     motor vehicles of every kind and description, and all articles from metal,
     wood, cloth, plastics or any other substances, implements and tools and
     devices which may be necessary, useful and convenient in the assembling,
     repairing, remodeling, or servicing thereof.

          To purchase, assemble, lease, import or otherwise acquire, handle,
     own, hold, invest in, exchange, store, care for, repair, remodel, service,
     equip, maintain, operate, let, mortgage, pledge or otherwise encumber,
     sell, export, assign, distribute, at wholesale or retail, whether

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     as principal or agent or jobber, whether on commission, consignment, lease,
     or otherwise, licence the sale of, export, and in any other manner dispose
     of, and generally to deal in, trade in and traffic in or otherwise turn to
     account, tank cars, railroad cars, automobiles, trucks, omnibuses,
     taxicabs, vans, trailers, racing cars, armored cars, ambulances, airplanes
     of all kinds and description, motorcycles, motor boats and other automotive
     vehicles and conveyances, propelled by internal combustion motors or motors
     of any other type, nature or description, wagons, buggies and carriages of
     all nature and description.

          To establish and maintain garages with authority to purchase, sell,
     store, house, rent, operate, repair and otherwise deal in automobiles and
     other motor vehicles and their accessories, gasoline, and oils necessary to
     the operation of motor vehicles.

          To engage in the business of acquiring, holding, improving, developing
     or disposing of interests in real property of every kind and character, as
     a principal or in a representative capacity, and to accumulate and lend
     money for those purposes.

          To erect, remodel or repair any building or improvement, and to
     accumulate and lend money for said purposes, and to purchase, sell and
     subdivide real property in towns, cities and villages and their suburbs not
     extending more than two miles beyond their limits, and to accumulate and
     lend money for that purpose.

          To manage and/or operate, as a principal or in a representative
     capacity, any type of real property, including, but not limited to,
     commercial office buildings, public and private warehouses, parking
     garages, shopping centers, apartments and other dwelling units,
     manufacturing and other industrial buildings.

          To acquire, hold, operate or manage and dispose of farm and ranch
     properties, as a principal or in a representative capacity.

          To acquire by purchase, subscription, contract or otherwise, and to
     hold for investment or otherwise, sell, exchange, mortgage, pledge,
     hypothecate, or otherwise dispose of, or turn to account or realize upon,
     and generally to deal in acid with all forms of securities, mortgages,
     loans, including, but not by way of limitation, shares, stocks, bonds,
     debentures, notes, scrip, warrants, rights,

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     mortgages, evidences of indebtedness, certificates of indebtedness,
     individual loans, broker loans, and certificates of interest issued or
     created in any and all parts of the world by corporations, associations,
     partnerships, firms, trustees, syndicates, individuals, governments,
     states, municipalities or other political or governmental divisions or
     subdivisions, or by any combinations, organizations, or entities
     whatsoever, or issued or created by others irrespective of their form or
     the name by which they may be described, and all trust, participation and
     other certificates of, and receipts evidencing, interest in any such
     securities, and to issue in exchange, transfer or in payment thereof, in
     any manner permitted by law, its own stock, bonds, debentures or its other
     obligations or securities, subject to the provisions of this Certificate or
     to make payment therefor by any other lawful means of payment whatsoever;
     to exercise any and all rights, powers, and privileges of individual
     ownership or interest in respect of any and all such securities or
     evidences of interest therein, including the right to vote thereon and to
     consent and otherwise act with respect thereto: to do any and all acts and
     things for the preservation, protection, improvement and enhancement in
     value of any and all such securities or evidences of interest therein, and
     to aid by loan, subsidy, guaranty or otherwise those issuing, creating, or
     responsible for any such securities or evidences of interest therein; to
     acquire or become interested in any such securities or evidences of
     interest therein as aforesaid, by original subscription, underwriting,
     loan, participation in syndicates or otherwise and irrespective of whether
     or not such securities or evidences of interest therein be fully paid or
     subject of further payments; to make payments thereon as called for in
     advance of calls or otherwise, and to underwrite or subscribe for the same
     conditionally or otherwise, and either with a view to investment or for
     resale or for any other lawful purpose.

          To enter into partnership or into any arrangement for sharing of
     profits, union of interests, co-operation, joint adventure, reciprocal
     concession or otherwise, with any person or corporation carrying on or
     engaged in or about to carry on or engage in any business or transaction
     which the corporation is authorized to carry on or engage in, or any
     business or transaction capable of being conducted so as directly or
     indirectly to benefit the corporation; and to lend money to, guarantee the
     contracts of, or otherwise assist any such person or corporation, and to
     take or otherwise acquire shares and securities of any such corporation,
     and to sell, hold, reissue, with or without guaranty, or otherwise deal
     with the same.

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          To guarantee the payment of the principal of and interest upon any
     notes, debentures, bonds, or other evidences of indebtedness of any kind
     or character of any corporation, joint stock company, syndicate,
     association, firm, trust or person whatsoever.

          To manufacture, purchase, or otherwise acquire, invest in, own,
     mortgage, pledge, sell, assign and transfer or otherwise dispose of, trade,
     deal in and deal with goods, wares and merchandise and personal property of
     every class and description.

          To acquire, and pay for in cash, stock or bonds of this corporation or
     otherwise, the good will, rights, assets and property, and to undertake or
     assume the whole or any part of the obligations or liabilities of any
     person, firm, association or corporation.

          To acquire, hold, use, sell, assign, lease, grant licenses in respect
     of, mortgage or otherwise dispose of letters patent of the United States or
     any foreign country, patent rights, licenses and privileges, inventions,
     improvements and processes, copyrights, trademarks and trade names,
     relating to or useful in connection with any business of this corporation.

          To enter into, make and perform contracts of every kind and
     description with any person, firm, association, corporation, municipality,
     county, state, body politic or government or colony or dependency thereof.

          To borrow or raise moneys for any of the purposes of the corporation
     and, from time to time without limit as to amount, to draw, make, accept,
     endorse, execute and issue promissory notes, drafts, bills of exchange,
     warrants, bonds, debentures and other negotiable or non-negotiable
     instruments and evidences of indebtedness, and to secure the payment of any
     thereof and of the interest thereon by mortgage upon or pledge, conveyance
     or assignment in trust of the whole or any part of the property of the
     corporation, whether at the time owned or thereafter acquired, and to sell,
     pledge or otherwise dispose of such bonds or other obligations of the
     corporation for its corporate purposes.

          To loan to any person, firm or corporation any of its surplus funds,
     either with or without security.

          To purchase, hold, sell and transfer notes, debentures, bonds and
     other securities issued by this corporation and the shares of its own
     capital stock; provided, however,

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     that it shall not use its funds or property for the purchase of its own
     shares of capital stock when such use would cause any impairment of its
     capital except as otherwise permitted by law, and provided further that
     shares of its own capital stock belonging to it shall not be voted upon
     directly or indirectly.

               To transact any manufacturing or mining business and to purchase
     and sell goods, wares and merchandise used for such business; to engage in
     the business of producing, mining, manufacturing, buying and selling of
     building materials of all kinds; to establish and maintain an oil business
     with authority to contract for the lease and purchase of the right to
     prospect for, develop and use coal and other minerals, petroleum and gas;
     also the right to erect, build and own all necessary oil tanks, cars and
     pipes necessary for the operation of the business of the same; to establish
     and maintain a drilling business with authority to own and operate drilling
     rigs, machinery, tools and apparatus necessary in the boring or otherwise
     sinking of wells in the production of oil, gas or water, or either, and the
     purchase and sale of such goods, wares and merchandise used for such
     business; to engage in the business of storing, transporting, buying and
     selling oil, gas, salt, brine and other mineral solutions and liquefied
     minerals; also sand and clay for the manufacture and sale of clay products;
     to purchase and sell goods, wares and merchandise and agricultural and farm
     products.

               To have one or more offices, to carry on all or any of its
     operations and business and without restriction or limit as to amount to
     purchase or otherwise acquire, hold, own, mortgage, sell, convey or
     otherwise dispose of, real and personal property of every class and
     description in any of the states, districts, territories or colonies of the
     United States, and in any and all foreign countries, subject to the laws of
     such state, district, territory, colony or country.

               In general, to carry on any other business in connection with the
     foregoing, and to have and exercise all the powers conferred by the laws of
     Delaware upon corporations formed under the General Corporation Law of the
     State of Delaware, and to do any or all of the things hereinbefore set
     forth to the same extent as natural persons might or could do.

          The objects and purposes specified in the foregoing clauses shall,
except where otherwise expressed, be in nowise limited or restricted by
reference to, or inference from, the terms of any other clause in this
certificate of incorporation, but the objects and pur-

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poses specified in each of the foregoing clauses of this Article shall be
regarded as independent objects and purposes.

          FOURTH. The total number of shares of stock which the corporation
shall have authority to issue is two hundred fifty thousand (250,000) and the
par value of each or such shares is One Dollar ($1.00), amounting in the
aggregate to Two Hundred Fifty Thousand Dollars ($250,000.00).

          No holder of any stock of the corporation shall be entitled as a
matter of right to purchase or subscribe for any part of any stock of the
corporation, authorized by this certificate, or of any additional stock of any
class to be issued by reason of any increase of the authorized stock of the
corporation, or of any bonds, certificates of indebtedness, debentures or other
securities convertible into stock of the corporation, but any stock authorized
by this certificate or any such additional authorized issue of new stock or of
securities convertible into stock may be issued and disposed of by the Board of
Directors to such persons, firms, corporations or associations for such
consideration and upon such terms and in such manner as the Board of Directors
may in their discretion determine without offering any thereof on the same terms
or on any terms to the stockholders then of record or to any class of
stockholders.

          The corporation shall be entitled to treat the person in whose name
any share, right or option is registered as the owner thereof for all purposes
and shall not be bound to recognize any

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equitable or other claim to or interest in such share, right or option on the
part of any other person, whether or not the corporation shall have notice
thereof, save as may be expressly provided by the laws of the State of Delaware.

          A director shall be fully protected in relying in good faith upon the
books of account of the corporation or statements prepared by any of its
officials as to the value and amount of the assets, liabilities and/or net
profits of the corporation, or any other facts pertinent to the existence and
amount of surplus or other funds from which dividends might properly be declared
and paid.

          Without action by the stockholders, the shares of stock may be issued
by the corporation from time to time for such consideration as may be fixed from
time to time by the Board of Directors thereof, and any and all such shares so
issued, the full consideration for which has been paid or delivered, shall be
deemed fully paid stock and not liable to any further call or assessment
thereon, and the holder of such shares shall not be liable for any further call
or assessment thereon, or for any other payment thereon.

          FIFTH. The minimum amount of capital with which the corporation will
commence business is one Thousand and No/100 Dollars ($1,000.00).

          SIXTH. The name and place of residence of each of the incorporators
are as follows:

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               NAME                             RESIDENCE
               ----                             ---------

          R. F. Westover                   Wilmington, Delaware

          L. A. Schoonmaker                Wilmington, Delaware

          A. D. Atwell                     Wilmington, Delaware

          SEVENTH. The corporation is to have perpetual existence.

          EIGHTH. The private property of the stockholders shall not be subject
to the payment of corporate debts to any extent whatever.

          NINTH. All corporate powers shall be exercised by the Board of
Directors, except as otherwise provided by statute or by this Certificate of
Incorporation.

          The Directors of the corporation shall be elected by the stockholders
of the corporation at the time and in the manner specified in the By-laws of the
corporation; such election of directors need not be by ballot.

          TENTH. In furtherance and not in limitation of the powers conferred by
the laws of the State of Delaware, the Board of Directors is expressly
authorized:

          1. To fix, determine and vary from time to time the amount to be
maintained as surplus and the amount or amounts to be set apart as working
capital.

          2. To set apart out of any of the funds of the corporation

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available for dividends, a reserve or reserves for any proper purposes and/or
to abolish any such reserve in the manner in which it was created.

          3. To make, amend, alter, change, add to, or repeal By-laws for the
corporation without any action on the part of the stockholders. The By-laws made
by the directors may be amended, altered, changed, added to or repealed by the
stockholders.

          4. To authorize and cause to be executed mortgages and liens without
limit as to amount upon the real and personal property of the corporation,
including after-acquired property.

          5. From time to time to determine whether and to what extent and at
what times and places and under what conditions and regulations the books and
accounts of this corporation or any of them other than the stock ledger, shall
be open to the inspection of the stockholders, and no stockholder shall have any
right to inspect any account or book or document of the corporation, except as
conferred by law or authorized by resolution of the directors or of the stock
holders.

          6. To authorize the payment of compensation to the directors for
services to the corporation, including fees for attendance at meetings of the
Board of Directors, of the Executive Committee, and of other Committees, and to
determine the amount of such compensation and fees.

          7. To sell, lease or exchange all of its property and

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assets, including its good will and its corporate franchises upon such terms and
conditions and for such consideration which may be in whole or in part shares of
stock in and/or other securities of any other corporation or corporations when
and as authorized by the affirmative vote of the holders of a majority of the
stock issued and outstanding having voting power given at a stockholders'
meeting duly called for that purpose or when authorized by the written consent
of the holders of a majority of the voting stock issued and outstanding.

          8. This corporation may in its By-laws confer powers additional to the
foregoing upon the directors, in addition to the powers and authorities
expressly conferred upon them by law.

          ELEVENTH. No contract or other transaction between the corporation and
any other corporation and no other act of the corporation shall, in the absence
of fraud, be invalidated or in any way affected by the fact that any of the
directors of the corporation are pecuniarily or otherwise interested in such
contract, transaction or other act, or are directors or officers of such other
corporation. Any director of the corporation, individually, or any firm or
association of which any such director may be a member, may be a party to, or
may be pecuniarily or otherwise interested in, any contract or transaction of
the corporation, provided that the fact that he individually or such firm or
association is so interested shall be disclosed or shall have been known to the
Board of

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Directors; and any director of the corporation who is a director or officer of
such other corporation or who is so interested may be counted in determining the
existence of a quorum at any meeting of the Board of Directors which shall
authorize any such contract or transaction, and may vote thereat to authorize
any such contract or transaction with like force and effect as if he were not
such director or officer of such other corporation or not so interested, every
director of the corporation being hereby relieved from any disability which
might otherwise prevent him from carrying out transactions with or contracting
with the corporation for the benefit of himself or any firm, corporation,
association, trust or organization in which or with which he may be in anywise
interested or connected.

          Any contract, transaction or act of the corporation or of the Board of
Directors which shall be ratified by a quorum of the stockholders entitled to
vote at any annual meeting or at any special meeting called for that purpose
shall be as valid and binding as though ratified by every stockholder of the
corporation; provided, however, that any failure of the stockholders to approve
or ratify such contracts, transaction or act when and if submitted, shall not be
deemed in any way to invalidate the same or to deprive the corporation, its
directors or officers of their right to proceed with such contract, transaction
or action.

          TWELFTH. Any and all of this corporation's directors or officers or
former directors or officers or any person who may have

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served at this corporation's request as a director or officer of another
corporation in which this corporation owns shares of capital stock or of which
this corporation is a creditor, shall be indemnified against expenses actually
and necessarily incurred by them in connection with the defense of any action,
suit or proceeding in which they, or any of them, are made parties, or a party,
by reason of being or having been directors or officers or a director or officer
of this corporation, or of such other corporation, except in relation to matters
as to which any such director or officer or former director or officer or person
shall be adjudged in such action, suit or proceeding to be liable for negligence
or misconduct in the performance of duty. The foregoing right to indemnity shall
include reimbursement of the amounts and expenses paid in settling any such
action, suit or proceeding, when settling or a plea of nolo contendere appears
to be in the interest of the corporation. Such indemnification shall not be
deemed exclusive of any other rights to which those indemnified may be entitled
under any by-laws, agreement, vote of stockholder or otherwise.

          THIRTEENTH. Upon the written consent or vote of the holders of a
majority in aggregate number of the shares of stock of the corporation then
outstanding and entitled to vote, every statute of the State of Delaware (a)
increasing, diminishing or in any way affecting the rights, powers, or
privileges of stockholders of corporations organized under the general laws of
said State, or

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(b) giving effect to the action taken by any part, less than all, of the
stockholders of any such corporation, shall be binding upon the corporation and
every stockholder thereof to the same extent as if such statute had been in
force at the date of the making, filing and recording of this Certificate of
Incorporation of the corporation.

          FOURTEENTH. If the By-laws so provide, the stockholders, and directors
shall have power to hold their meetings, to have an office or offices and to
keep the books of this corporation (subject to the provisions of the statute),
outside the State of Delaware, at such places as may from time to time be
designated by the By-laws or by resolution of the directors.

          FIFTEENTH. This corporation reserves the right to amend, alter, change
or repeal any provision contained in this Certificate of Incorporation in the
manner now or hereafter prescribed by law, and all rights conferred on officers,
directors and stockholders herein are granted subject to this reservation.

          We, the undersigned, being all of the incorporators hereinbefore
named, for the purpose of forming a corporation pursuant to the General
Corporation Law of the State of Delaware, do make and file this Certificate of
Incorporation, hereby declaring and certifying that the facts herein stated are
true, and accordingly hereunto have set our respective hands and seals this
21st day of April, A. D. 1960.


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THE STATE OF DELAWARE      )

                           )   ss.

COUNTY OF NEW CASTLE       )

          BE IT REMEMBERED that on this 21st day of April, 1960, personally
appeared before me the subscriber, a Notary Public for the State and County
aforesaid, R.F. Westover, L. A. Schoonmaker and A. D. Atwell all the parties to
the foregoing Certificate of Incorporation, known to me personally to be such
and severally acknowledged the said Certificate to be their act and deed
respectively, and that the facts therein stated were truly set forth.

          GIVEN UNDER MY HAND AND SEAL OF OFFICE the day and year aforesaid.


                                                 /s/ Illegible
                                                 -------------------------------
                                                   Notary Public in and for
                                                  New Castle County, Delaware

                                                          [SEAL]

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