1933, souvenir sheet issue "international postal stamps exhibition Vienna Philatelic Exhibition, Vienna", original size 126 x 106 mm, cancelled by special cancel "Vienna Vienna Philatelic Exhibition 1933 Congress house a 24 / 6", including appurtenant cover, very fine, photo expertize Roger Söcknick BPP (2025) "genuine and immaculate", Michel 4.000.- - rare!