407.855.  Repurchase of farm machinery inventory on termination of dealership — repurchase amount credited to debt of retailers — interest to be paid on credit, when, rate. — Whenever any retailer enters into a written or oral contract with a wholesaler, manufacturer or distributor wherein the retailer agrees to maintain an inventory and the contract is terminated by the wholesaler, manufacturer, distributor, or retailer, or upon the retailer's retirement at sixty-two years of age or older, then the retailer may require the repurchase of the inventory as provided for in sections 407.850 to 407.885. In the event of the death of the retailer or the majority stockholder of a corporation operating as a retailer, the wholesaler, manufacturer or distributor shall repurchase the inventory as provided for in section 407.880.  If the retailer has any outstanding debts to the wholesaler, manufacturer or distributor, then the repurchase amount may be credited to the retailer's account.  All payments or allowances of credit due retailer shall be paid or credited within sixty days after the return of implements, machinery, attachments or repair parts.  After sixty days all payments or allowances shall include interest at the rate stated in section 408.040.