1917 (9 June) picture postcard (Warszawa), addressed to Leipzig, with violet "Ballon Zug 17 / Briefstempel" cachet, endorsed "Feldluftpost", with cds alongside, fine (Image)

Est.$150

1918 two flown covers, each franked with set of three, flown from Krakow (31.III.18) to Wien, the other from Wien (26.IV.18) to Lemberg, with Polish arrival pmks, fine-v.f., with Matl certificate (Cat No. C1-3) (Image)

Est.$250

1926 (1 Apr) Warszawa to Westerplatte/Gdansk, flown card with vertical strip of three of 10gr green, variety imperf. between top and middle stamps, used in combination with 2x2gr, 5gr and 25gr stamps, red "Durch Eilboten Expres" label and "Mit Luftpost befordert Flugpostampt Danzig 5" handstamp, fine and possibly only known card with 10gr L.O.P.P. imperf. between, ex-Boonshaft (Image)

Est.$500

1926 (13 June) Warszawa to Krakow, flown cover with attractive franking, additionally charged 5gr, with framed "Pobrano/Percu" cachet, oval "Poczta Lotnicza Wystawa Radiowa" bilingual (Air Mail Radio Exposition) and "Nadeszla Poczta Lotnicza" in violet, Krakow arrival pmk on back (Image)

Est.$150

1928 (24 Aug) registered and flown cover from Warszawa to Paris, franked with 5gr, 10gr, 25gr and 50gr L.O.P.P. surcharges, used in combination with 2x45gr, charged additional 50gr, with boxed "Pobrano/Percu" handstamp, some adhesive residue on back, ex-Boonshaft (Image)

Est.$500

1932 two flown covers, one from Warszawa to Wilno, the other from Lwow to Riga, each with first flight "Warszawa-Wilno-Riga-Tallinn" cachet and appropriate arrival pmks, fine-v.f. (Image)

Est.$250