Air Post stamps. 1934, Camels and Airplane, imperforated trial color proof of 5k in ultra, printed on watermarked paper, nice margins all around, full OG, NH, VF, an issued stamp is included, A. Farberov certificate (Image)

Air Post stamps. 1934, Yaks and Airplane, imperforated trial color proof of 50k in ultra, printed on watermarked paper, enlarged margins at the top and bottom, flawless condition, full OG, NH, VF, an issued stamp is included, A. Farberov certificate (Image)

Air Post stamps. 1936, 15th Anniversary of the Republic, Airplane and Dirigible, 5k-3a, complete set of nine, including triangle and diamond stamps, fresh and choice, full OG, NH, VF (Image)