Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Latvia - 1928 (May 10-11), Deruluft Flight cover from Riga to Moscow, franked by ''Bleriot IX'' complete set of three triangle stamps and Arms stamp of 5s on reverse, Deruluft bilingual confirmation marking and arrival ds on reverse, mostly VF, Est. $100-$150, Sc. #C3-5