Bidspirit auction | Worldwide Air Post Stamps and

Worldwide Air Post Stamps and Postal History - Poland - Zeppelin Flights - 1932 (August 29-September 1), 5th South America Flight pre-printed registered cover to Brazil, franked by 11 air post values (eight on reverse), tied by Warsaw ''25.VIII.32'' ds, red Berlin-Friedrichshafen connection and violet flight markings, Pernambuco arrival hs on reverse, blue envelope ink absorbed through stamp paper, still F/VF, Sieger #171, Est. $250-$300, Scott #C7, C9 x10