Air Post stamps. 1924, Aviation School, 10c, 25c and 2b, imperforated set of three, nice margins all around, full OG, LH, VF, only 100 imperforated stamps of each denomination were produced, Sanabria #8, 10 and 12, C.v. $600 (1966) (Image)

Air Post stamps. 1930, inverted Zeppelin surcharges or overprints, 5c on 10c, 15c and 25c, set of three values, full OG, LH or previously hinged, F/VF, C.v. $300, which is strongly undervalued, no more then 300 stamps of each denomination possible (Image)