Poland. Michel 329 cover , 1938 Polish Stratosphere Balloon souvenir sheet 6 (1) on card (small creases) carried by the balloon, cancelled ZAKOPANE 24.IX.38 to Warsaw + Austria, registered air mail cover by "SAS ERÖFFNUNGSFLUG EUROPA-NORDPOL-LOS ANGELES", cancelled St Veit/Glan 11.11.54 (One Polish and one Austrian cover).