1926-29, Two diff. balloon flight pcs plus a cover, two with 1Z special balloon flight labels, third with 1929 Int’l Balloon Contest label (all tied by appropriate cds or hs), sent from Swislocz (1926, balloon “Poznan” with Warsaw airmail receiver), Maloryta (1928, balloon “Krakow”) and Poznan (to Leipzig, balloon “Sérénite”), elusive, gen. very fine (Mü. 35, 56, 74c; total 1’300pts) (Image)

1936 (May) Zeppelin Hindenburg 1st North America Flight, reg’d cover with ms currency export controls from Bydgoscz with 3Z tied (May 4), sent to New York and ret’d to sender (hs), the reverse with a galaxy of bs incl. Berlin (May 6), various New York ovals and several Poznan bs (May 4, May 20-21) and final of Bydgoscz (May 21), scarce, fine (Sieger 406, € 350) (Image)