A striking Uruguayan commemorative featuring a bold black overprint celebrating the 50th Anniversary of the Sociedad de Arquitectos del Uruguay. Issued on the earlier Recuperación Nacional semi-postal design, the stamp shows an allegorical figure looking toward agricultural fields and a rising sun, symbolizing national renewal. This variety includes the 4 centésimos surcharge + 10c additional postal tax, applied over the original design. Highly collectible for students of Uruguay overprints, semi-postals, and anniversary issues, particularly due to its clean typography and strong thematic connection to architecture and national development. A fine addition to mid-20th-century Latin American philately.