Poland, Michel 329 or Scott B31 cover, 1938 Polish Stratosphere Balloon souvenir sheet 6 (1). Special postcard sent from the first stratosphere balloon flight in Poland 1938, franked on the back side with Block 8. cancelled in Zakopane 20.IX.1938. (Image1)

Poland, Air mail cover 1934, Michel 285-86 Cover from the stamp exhibition in Katovice 1934, franked with the two special stamps for this exhibition. Cancelled on the first day of the exhibition. Arrival cds on the back side of the cover. (Image1)