Air Post stamps. 1931, Airmail Pictorial issue, complete set of three imperforated plate proofs in black, printed on thick unwatermarked (15k) or watermarked paper, no gum as produced, VF and rare (Image)

Air Post stamps. 1932, Dornier DO-X Flight, red surcharge $1.50 on $1 blue, nicely centered, minimal offset on gum side, full OG, NH, VF, Unitrade C.v. $700 (Image)

Air Post stamps. 1933, General Balbo Flight, black surcharge $4.50 on 75c bister, surcharge from position 4 of four-stamp setting, slightly blurry as often, full OG, NH, VF, Unitrade C.v. C$800 (Image)