Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Poland - 1938, Attempt of Stratosphere Flight by Major Burzynski and Professor Jadko-Narkiewicz, two souvenir sheets of different shades (one is defected) and three Balloon postcards, two of which with cancelled souvenir sheets, mostly F/VF, Est. $150-$200, Sc. #B31