cover 1912 (May) Leipzig-Lindenthal Flight, 50pf. pale blue (3) affixed to postcards and the ultramarine shade affixed to an envelope, all in combination with regular values - one is on an Austrian 5h. stationery card, all vignettes cancelled by framed "Durch Flugpost" d.s. Fine. M. 4a/b, DM.2150