Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia and Soviet Union - 1937, Aviation Exhibition, 10k-1r, complete set of seven, and souvenir sheet of 1r x4, both items with full OG, NH, VF, C.v. $624, Est. $250-$300 , Scott #C69-75, C75a