Mo. Rev. Stat. § 408.270
Retail time contracts negotiated and entered into by mail without personal solicitation by salesmen or other representatives of the seller and based upon the catalog of the seller or other printed solicitation of business, which is distributed and made available generally to the public, if such catalog or other printed solicitation clearly sets forth the cash and time sale prices and other terms of sales to be made through such medium, may be made as provided in this section. All provisions of sections 408.250 to 408.370 shall apply to such sales except that the seller shall not be required to deliver a copy of the contract to the buyer as provided in section 408.260 and if the contract when received by the seller contains any blank spaces the seller may insert in the appropriate blank space the amounts of money and other terms which are set forth in the seller's catalog or other printed solicitation which is then in effect. In lieu of sending the buyer a copy of the contract as provided in section 408.260, the seller shall furnish to the buyer a written statement of any items inserted in the blank spaces in the contract received from the buyer.
§ 408.270, RSMo