Auction #93 Worldwide Air Post stamps and postal history, Zeppelin Flight items, philatelic rarities of the World

KOWEL (WOLYN GOVT.): 1919, violet handstamp ''Poczta Polska. 50 fen'' over violet Kyiv trident overprint (type 2) on Russian 1r dark brown, pale brown and orange, vertical imperforated pair, full OG, NH, VF, each stamp expertized by H. Bloch, Fischer #5, C.v. PLN560=US$140