Air Post stamps and covers. 1941, First Flight ‘‘Liberia – U.S.’’, black surcharges 50c on 4c, 5c x2 (one with surcharge shifted to the right) and 30c, overprint on 50c, set of five values, full OG, NH (3) or LH, VF, each one expertized by F. Kessler and others, C.v. $420++ (Image)

Air Post stamps and covers. 1942, set of four covers in commemoration of the First Flight ‘‘Liberia – U.S.’’, each one bearing surcharge of 50c on 5c, 10c, 30c or overprint on 50c, all with commemorative cancel, three with ‘‘Aviation History’’ pre-print, VF, nice group for a specialist, Postal Department Notice about these stamps is included (Image)

Air Post stamps and covers. 1942, two stamps of 4c in yellow or orange with Bars overprint over black surcharge ‘‘First Flight. Liberia – U.S. 1941’’ 50c, first one has double bars overprint, which is very scarce, priced in Sanabria of 1966 for $150, the other one with bars shifted below of ‘‘1941’’, full OG, NH or VLH (double overprint), VF, both with Sanabria and F. Kessler guarantees (Image)

Air Post stamps and covers. 1942, black Bars overprint over First Flight surcharge 50c on 5c green, tete-beche block of four triangle stamps, left stamp with added bars, which are longer and thinner then original ones, pre-printing paper fold, nice full OG, NH, VF and very rare (Image)

Air Post stamps and covers. 1944, violet or black surcharges 10c on 2c in right sheet margin block of four, 30c on 1c in tete-beche pair, and $1 on 50c is a single, full or large part of OG (C46A), NH or LH/hinged, VF, each stamp with J. Stolow guarantee hs, C.v. $503 (Image)

Air Post stamps and covers. 1944-45, black surcharge 30c on 4c, a single and two tete-beche pairs, two diagonally placed surcharges and left stamp of horizontal tete-beche without obliterating overprint, in addition violet surcharge $1 on 50c in horizontal strip of three, central stamp with incorrectly placed bars obliterating value, full OG, NH, VF, all varieties with J. Stolow guarantee hs (Image)

Air Post stamps and covers. 1944, dark blue surcharge $1 on 3c olive green, block of four and a single, bottom right stamp of the block has surcharge ‘‘$.100’’, while a single with double surcharge, full OG, NH (block of four) or LH, VF and rare, a single with J. Stolow guarantee hs, Sanabria of 1966 priced the first error at $120 and the second one at $150 (Image)