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                                                                    EXHIBIT 10.8


                                PROMISSORY NOTE


U.S. $250,000                                Miami, Florida May 12th, 1997

     FOR VALUE RECEIVED, the undersigned (jointly and severally, if more than
one) promises to pay to the order of SILVERTOWN INTERNATIONAL CORP., a
corporation organized the laws of the country of Panama, the principal sum of
Two Hundred Fifty Thousand U.S. Dollars ($250,000.00), together with interest
thereon from date, at the rate of 6% (PERCENT) per annum until maturity on the
balance from time to time remaining unpaid.  Said principal and interest shall
be payable in lawful money of the United States of America at Miami, Florida,
or at such place as may hereafter be designated by written notice from the
holder to the maker hereof, on the date(s) and in the amounts specified below:

     Principal together with accrued interest are due and
     payable on or before two and one half (2 1/2) months
     from the date hereof.

     The undersigned has the option to extend the payment term on this note for
an additional two and one half (2 1/2) months.  Such option may be exercised by
providing written notice to the holder hereof by the undersigned no later than
five (5) days before the due date hereof.  If the undersigned chooses to extend
the payment term, then this note will bear interest at 6% (PERCENT) per annum
until maturity on the balance then remaining unpaid.

     All payments shall apply first to accrued interest, and the remainder, if
any, to reduction of principal.  If any installment of principal is not paid
when due, or upon any default in the performance of any of the convenants or
agreements of this note, or of any instrument now or hereafter evidencing or
securing this note or the obligation represented hereby, the whole indebtedness
(including principal and interest) remaining unpaid, shall, at the option of
the holder, become immediately due, payable and collectible, and while in
default, this note and deferred interest shall bear interest at the rate of 12%
(PERCENT) per annum.  Each maker and endorser severally waives demand, protest
and notice of maturity, non-payment or protest and all requirements necessary
to hold each of them liable as makers and endorsers.  Each maker and endorser
further agrees, jointly and severally, to pay all costs of collection,
including reasonable attorney fees in case the principal of this note or any
payment on the principal or any interest thereon is not paid at the respective
maturity thereof, or in case it becomes necessary to protect the security
hereof, whether suit be brought or not.


                                        JET AVIATION TRADING, INC.



Payable at Miami, Florida, U.S.A.       By: /s/ Joseph J. Nelson, 
           -----------------------         ---------------------------------
                                           Joseph J. Nelson, President


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or such other place as shall be
designated by the holder of this
note in writing.