Used cover with Michel 1067 from Siegendorf to Vienna, 23.05.1961

Used cover from Siegendorf (Austria) to Vienna (Austria) on 23 May 1961, balloon mail, franked with the Austrian stamp 1.50 Schilling "Tirol" Michel 1067, with 2 special cancellations "Luposta Ballonpost" and the local postmark "Siegendorf 1 a 23.5.61-17"