Mo. Rev. Stat. § 177.071
All sales of land in sections numbered sixteen, or lands selected in lieu thereof, by any sheriff, in the attempt to carry out the provisions of any statute relating to the sale of the lands as school lands for the townships in which they lie, which sales took place more than ten years before October 13, 1963, shall, upon the expiration of two years from October 13, 1963, become and be deemed valid and effectual for all intents and purposes, and the title thereto sought to be conveyed is hereby confirmed in the respective purchasers and those claiming under them at the expiration of the two years, whether there was any petition from the householders of the townships for the sales or not, and notwithstanding any other errors, defects, omissions or imperfections in the petition, order of sale, notice, sale, or other proceeding therein; save only as to such lands now involved or which during the period of two years may become involved in any suit because thereof, as to which lands this section shall not take effect until the final determination of the suit.
§ 177.071, RSMo