Document:

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                                                                   EXHIBIT 10.30

TEXAS SIMPLE INTEREST VEHICLE RETAIL INSTALMENT CONTRACT          DATE  05/14/99

Buyer (and Co-Buyer) Name and Address (Including County and Zip Code)
                     Simpco, Inc.
                     P.O. Box 828
                     Zephyr, TX 76890-0828

CREDITOR (Seller Name and Address)
                     Clemons Motor Co., Inc.
                     P.O. Box 241
                     Comanche, TX 76442-0241

YOU, THE BUYER (AND CO-BUYER, IF ANY), MAY BUY THE VEHICLE DESCRIBED BELOW FOR
CASH OR ON CREDIT. THE CASH PRICE IS SHOWN BELOW AS "CASH PRICE." THE CREDIT
PRICE IS SHOWN AS "TOTAL SALE PRICE." BY SIGNING THIS CONTRACT, YOU CHOOSE TO
BUY THE VEHICLE ON CREDIT UNDER THE AGREEMENTS ON THE FRONT AND BACK OF THIS
CONTRACT.

<TABLE>
<CAPTION>
New/Used  Year and Make     Model       GVW if Truck (lbs.)    Vehicle Identification Number       Use For Which Purchased
--------  -------------     -----       -------------------    -----------------------------       -----------------------
<S>       <C>             <C>           <C>                    <C>                              <C>
  Used     1996 Ford      F350 CrCb                                  1FTJW35F6TEB56911          [ ] Personal        [ ] Agricultural
                                                                                                [X] Commercial
</TABLE>

Trade-in      n/a         $       n/a           $       n/a
        --------------     -----------------     -----------------
         Year and make      Gross Allowance         Amount Owing

                         ITEMIZATION OF AMOUNT FINANCED

1. Cash Price................................................... $ 19596.52 (1)
                                                                   --------
2. Down Payment
   Third Party Rebate Assigned To Creditor................ $   n/a
                                                            ---------
   Cash Down Payment...................................... $ 3903.00
                                                            ---------
   Deferred Down Payment due.............................. $   n/a
                                                            ---------
   Trade-in (description above) .......................... $   n/a
                                                            ---------
   Total Down Payment .......................................... $  3903.00 (2)
                                                                  ---------
3. Unpaid Balance of Cash Price (1 minus 2) .................... $ 15693.52 (3)
                                                                  ---------
4. Amounts paid on your behalf (Seller may be retaining a portion of these
   amounts)
   To Public Officials (i) for license, title & registration fees $      ;
                                                                   ------
     (ii) for filing fees $ n/a;
                           ----
     (iii) for Vehicle Inventory Tax $ 31.48;
                                      ------
     (iv) for taxes (not in Cash Price)     n/a        $  31.48
                                         --------       --------
   To Insurance Companies for
     Vehicle Insurance ............................ $ n/a
                                                     ----
     Credit Life Insurance ........................ $ n/a
                                                     ----
     Credit Disability Insurance .................. $ n/a
                                                     ----
     n/a........................................... $ n/a
                                                     ----
         Total Cost of Insurance .............................. $ n/a
                                                                 ------
   To Clamons Motor Co.,Inc for Documentary Fee ............... $ 50.00
      ---------------------                                      ------
       (Name of Creditor)

A DOCUMENTARY FEE IS NOT AN OFFICIAL FEE. A DOCUMENTARY FEE IS NOT REQUIRED BY
LAW, BUT MAY BE CHARGED TO BUYERS FOR HANDLING DOCUMENTS AND PERFORMING SERVICES
RELATED TO THE CLOSING OF A SALE. A DOCUMENTARY FEE MAY NOT EXCEED $50. THIS
NOTICE IS REQUIRED BY LAW.

  To           n/a            for             n/a           $      n/a
     ------------------------     -------------------------   --------------
  To           n/a            for             n/a           $      n/a
     ------------------------     -------------------------   --------------
  To           n/a            for             n/a           $      n/a
     ------------------------     -------------------------   --------------
  To           n/a            for             n/a           $      n/a
     ------------------------     -------------------------   --------------
      Total ............................................... $    81.48 (4)
                                                              --------------
5. Amount Financed (3 plus 4) ............... ............. $ 15775.00 (5)
                                                              --------------

                      FEDERAL TRUTH-IN-LENDING DISCLOSURES

<TABLE>
<CAPTION>
 ANNUAL PERCENTAGE RATE           FINANCE                   AMOUNT              TOTAL OF PAYMENTS            TOTAL SALE
    The cost of your               CHARGE                  FINANCED              The amount you                 PRICE
credit as a yearly rate      The dollar amount          The amount of            will have paid            The total cost
                             the credit will          credit provided to         when you have           of your purchase on
                                  cost you                you or on            made all scheduled               credit,
                                                         your behalf                 payments              including your
                                                                                                            downpayment
                                                                                                             of $ 3903.00
<S>                          <C>                      <C>                       <C>                       <C>
         10.00       %       $     2549.36            $     15775.00             $    18324.36              $   22227.36
---------------------         ----------------         -----------------          --------------             --------------
</TABLE>

                         Number of        Amount of Each       When Payments
Payment Schedule          Payments           Payment              are due
Your payment schedule       36              $  509.01        (monthly starting)
                          -------            --------
will be:                  1 final           $   n/a              06/25/99
                                             --------         ----------------

PREPAYMENT: If you pay off your debt early, you will not have to pay a penalty.

SECURITY INTEREST: YOU are giving a security interest in the vehicle being
purchased.

CONTRACT: Please see this contract for additional information on security
interest, nonpayment, default, the right to require repayment of your debt in
full before the scheduled date, and prepayment penalty.

   ANY CHANGE IN THIS CONTRACT MUST BE IN WRITING AND SIGNED BY YOU AND THE
CREDITOR.

BUYER:                                CO-BUYER:
      -----------------------------            --------------------------------

                              NOTICE TO THE BUYER:

DO NOT SIGN THIS CONTRACT BEFORE YOU READ IT OR IF IT CONTAINS ANY BLANK SPACES.
YOU ARE ENTITLED TO A COPY OF THE CONTRACT YOU SIGN. KEEP THIS CONTRACT TO
PROTECT YOUR LEGAL RIGHTS.

BUYER ACKNOWLEDGES RECEIPT OF A TRUE AND COMPLETELY FILLED IN COPY OF THIS
CONTRACT AT THE TIME OF SIGNING

SIMPCO, INC.
By: /s/ Richard C. Smith

-----------------------------------            ---------------------------------
           BUYER SIGNS                                 (CO)BUYER SIGNS

BY SIGNING BELOW, THE SELLER ACCEPTS THIS CONTRACT. IF NO OTHER ASSIGNEE IS
NAMED IN A SEPARATE ASSIGNMENT ATTACHED TO THIS CONTRACT, THE SELLER ASSIGNS IT
TO FORD MOTOR CREDIT COMPANY.

SELLER Clemons Motor Co., Inc.       By                   Title Sales Manager
       ----------------------------    -----------------        ----------------

                                    INSURANCE

YOU MAY OBTAIN VEHICLE INSURANCE FROM A PERSON OF YOUR CHOICE.

LIABILITY INSURANCE COVERAGE FOR BODILY INJURY AND PROPERTY DAMAGE CAUSED TO
OTHERS IS NOT INCLUDED.

CREDIT LIFE, CREDIT DISABILITY AND OTHER OPTIONAL INSURANCE ARE NOT REQUIRED TO
OBTAIN CREDIT AND WILL NOT BE PROVIDED UNLESS YOU SIGN AND AGREE TO PAY THE
PREMIUM.

Credit
 Life                                 n/a
     ---------------------------------------------------------------------------
                                     Insurer

$             n/a                                       n/a
 ------------------------------        -----------------------------------------
            Premium                                  Insured(s)

                                      n/a
--------------------------------------------------------------------------------
                                   Signature

Credit
 Disability                           n/a
            --------------------------------------------------------------------
                                    Insurer

$             n/a                                       n/a
 ------------------------------        -----------------------------------------
            Premium                                  Insured(s)

                                      n/a
--------------------------------------------------------------------------------
                                   Signature

                     n/a                                        n/a
----------------------------------------------     -----------------------------
                Type of Insurance                              Term

                     n/a                          $             n/a
----------------------------------------------     -----------------------------
                   Insurer                                    Premium

                                      n/a
--------------------------------------------------------------------------------
                                    Signature

CREDIT LIFE AND CREDIT DISABILITY INSURANCE ARE FOR THE TERM OF THE CONTRACT.
THE AMOUNT AND COVERAGES ARE SHOWN IN A NOTICE OR AGREEMENT GIVEN TO YOU TODAY.

YOU ARE REQUIRED TO INSURE THE VEHICLE. YOU MAY CHOOSE THE PERSON THROUGH WHOM
SUCH INSURANCE IS TO BE OBTAINED. YOU SHALL HAVE THE OPTION OF FURNISHING THE
INSURANCE OWNED OR CONTROLLED BY YOU OR OBTAINED BY YOU THROUGH ANY INSURANCE
COMPANY AUTHORIZED TO TRANSACT BUSINESS IN TEXAS. IF A CHARGE IS SHOWN BELOW,
THE CREDITOR WILL TRY TO BUY THE COVERAGES CHECKED FOR THE TERM SHOWN. COVERAGES
WILL BE BASED ON THE CASH VALUE OF THE VEHICLE AT THE TIME OF LOSS, BUT NOT MORE
THAN THE LIMITS OF THE POLICY.

       Comprehensive        $   n/a     Deductible
                              --------  Collision
       Fire-Theft-Combined Additional Coverage
       Towing and Labor
       Term     n/a      Months (Estimate)
           -------------
       Premium $         n/a
                ---------------------

       IF CHECKED, THE PREMIUM FOR PHYSICAL DAMAGE INSURANCE INCLUDED HEREIN IS
AT A RATE OF CHARGE NOT FIXED OR APPROVED BY THE STATE BOARD OF INSURANCE OF
TEXAS. THE BUYER SHALL HAVE THE OPTION FOR A PERIOD OF TEN DAYS FROM THE DATE OF
THIS CONTRACT OF FURNISHING THE REQUIRED INSURANCE COVERAGE EITHER THROUGH
EXISTING POLICIES OF INSURANCE OWNED OR CONTROLLED BY HIM OR OF PROCURING AND
FURNISHING EQUIVALENT INSURANCE COMPANY AUTHORIZED TO TRANSACT BUSINESS IN
TEXAS.

IF ANY OF THE ABOVE INSURANCE IS CANCELLED, THE CREDITOR WILL GIVE YOU A CREDIT
FOR ANY UNEARNED INSURANCE PREMIUMS THE CREDITOR GETS. THE CREDIT WILL BE MADE
TO THE LAST PAYMENTS DUE.<PAGE>   1
                                                                   EXHIBIT 10.31

                                 PROMISSORY NOTE

                                    (Demand)

         FOR VALUE RECEIVED, the undersigned jointly and severally promise to
pay to the order of Baldwin & Klein Corporation the sum of THIRTY THOUSAND &
NO/100 ($30,000.00) Dollars, together with interest of 0 % per annum on the
unpaid balance. The entire unpaid principal and any accrued interest shall be
immediately payable 3 YRS FROM DATE.

         Upon default in making payment within 10 days of demand, the
undersigned agree to pay all reasonable legal fees and costs of collection to
the extent permitted by state law. This note shall take effect as a sealed
instrument and be enforced in accordance with the laws of the payee's state.

Dated: 15 APRIL 1999
                                                       SIMPCO, INC.,

                                                       By: /s/ B WALKER
                                                          ----------------------
                                                               Bryan Walker,
                                                               President

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