Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Russia And Soviet Union - 1931, North Pole Zeppelin Flight and Ice-Breaker ''Malygin'', perforated (comb 12x12?) complete set of four used on registered cover from Nagayevo (Far Eastern Region) to San Francisco in 1937, backstamped ''Oct. 8. 1937'', minor reversal soiling, still VF and scarce complete set franking on non-Zeppelin cover, Scott #C30- 33, Est. $600-$700, Scott #C30-33