Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Latvia - Pioneer Flight - 1928 (May 10-11), Deruluft flight pre-printed cover from Riga to Moscow, franked by ''Bleriot XI'' 10s, 15s and 25s, complete set of three, Riga machine cancel and Deruluft confirmation marking, Moscow arrival ds on reverse, mostly VF, Est. $150-$180, Scott #C3-5