Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia and Soviet Union - 1933-44, Stratostat ''USSR'', 5k, 10k and 20k, complete set of three, in addition 10th Anniversary of the Stratosphere Disaster, complete set of three in corner margin blocks of four, all with full OG, NH, VF, C.v. $583 as singles, Est. $250-300, Scott #C37-39, C77-79