Zeppelin Flight. 1931 (April 11-13), Egypt Return Flight postcard (Graf von Zeppelin) to Germany, franked by three non-Zeppelin stamps, cancelled Cairo ''11.AP.31'' ds, straight line violet confirmation marking and Friedrichshafen ''13.4.31'' arrival hs, VF, Mi #166A III, €500, Est. $250-$300 (Image)