Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia and Soviet Union - Pioneer Flights - 1923-24, two registered covers sent from Moscow via Koenigsberg to Berlin on July 5, 1923 and June 17, 1924, first one franked by four stamps of peasant 5r blue, the other one is Philatelic Exchange cover bearing ''Fokker'' surcharged set of four and duty stamp on reverse, all appropriate markings and arrival ds, F/VF, Est. $300-$350, Scott #240, C6-9