Zeppelin Flights. 1930 (September 10-11), Moscow Return Flight stationery postcard and cover, franked by Zeppelin stamps of 40k ultra and 80k carmine respectively together with other values, tied by Moscow ''10-IX-30'' special date stamp, violet two-line confirmation cachet and Friedrichshafen ''11.9.30'' receiver, cover has slight fold away from the stamps, still VF, Est. $100-$150 (Image)

Zeppelin Flights. 1931 (July 25-27), North Pole Flight registered cover from Leningrad to Ice-Breaker ''Malygin'', franked by perforated 30k, 35k, 1r and 2r, complete set of four, tied by Leningrad special ds, red confirmation cachet and other appropriate markings, Ice-Breaker ''27.VII.31'' drop and Moscow receiver, VF and scarce, H. Sieger certificate, Est. $700-$800 (Image)

Zeppelin Flights. 1933 (August 5-8), 4th SAF registered cover from Leningrad to Brazil, franked by four Airship values, delivered by flight Leningrad - Berlin with connection ''29.7.33'' ds on reverse, two confirmation markings in red and Curitiba arrival hs, F/VF and scarce, Est. $450-$500 (Image)