Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Soviet Union - 1932 (August 29), International Polar Year, 50k carmine (perf 12) and 1r green (perf 10½), complete set of two used on registered air mail cover from Moscow to USA via Berlin, transit and arrival markings on reverse, VF and scarce complete set franking of non-Polar cover, Est. $250-$300, Sc. #C34-35