Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia And Soviet Union - Zeppelin Flights - 1931 (July 27-31), North Pole Return Flight card and cover from Ice-Breaker ''Malygin'' to Germany, franked by specially issued imperforate complete set of four, 30k and 1r for card and 35k and 2r for cover, cancelled ''18.VII.31'' by special date stamp, German confirmation cachet, Friedrichshafen ''31.7.31'' arrival handstamp and all appropriate markings, VF, Sieger #120Aa, Ab, Est. $300-$350, Scott #C26-29