Lot 329
1912, Borck-Brück Flight, Airmail stamp with Germania 3 pfg. with perfin "GR" (= Georg Rothgießer, Founder of the Airfield MARS) on printed matter envelope from "BRÜCK 5.3.12" to Schoningen with adjacent blue cachet "Flugpost Bork und Umgegend durch Gradeflieger", very fine and rare, Sieger BPP certificate