Air Post stamps. 1930, Airplane over Mountains and Vaduz Castle, 15rp-1fr, complete set of six, in addition black surcharge 60rp on 1fr lake, fresh quality, full OG, NH, VF, C.v. $648, SBK #F1-6, F16, C.v. CHF970, Est. $180-$240 (Image)

Air Post stamps. 1931, Zeppelin over Naafkopf Mountains, 1fr olive black and 2fr indigo, complete set of two, nice centering and intact perforation, full OG, NH, VF, C.v. $565, SBK #F7-8, C.v. CHF800, Est. $180-$240 (Image)

Air Post stamps. 1936, Eagles, 10rp-50rp, complete set of five, grilled gum, bottom sheet margin blocks of six (2x3), full OG, NH (hinged on margins only), VF, C.v. $1,500, SBK #F9z-13z, CHF2,040++, Est. $300-$400 (Image)