1923/1928, SERVICIO DE TRANSPORTES AEREOS EN COLOMBIA three values in different quantities incl. 60c. brown (85), 80c. olive-green (50) and 1p. grey (170) mostly in large blocks/part sheets, mint never hinged some with typical uneven gum, Mi. 35/36 + 44, € 5.130,-- +

1928, "50 Cts. 50" on 10c. green, fresh colour and well perforated, mint original gum (never hinged but some slight adhesion marks), signed. SG 6; Scott C6; Yvert A1. 2.100,- €. Only 100 surcharged. (Image)

1928, "50 Cts. 50" on 10c. green, fresh colour and well perforated, mint original gum (never hinged but some slight adhesion marks), signed. SG 6; Scott C6; Yvert A1. 2.100,- €. Only 100 surcharged. (Image)

1928, "50 Cts. 50" on 10c. green, block of four, fresh colour and well perforated, mint original gum (never hinged but some slight adhesion marks), signed and certificate Holcombe. SG 6; Scott C6; Yvert A1 (8.400,- €, price for four single stamps). Only 100 surcharged. (Image)

1929, "ECUADOR PROVISIONAL 75" on 15 C. red in Type II (41°, 18,5 mm long) tied by black hand roller stamp "GUAYAQUIL / 26 III 1928 (wrong year) / Luftpost in Ecuador / ...", uprated by Ecuador 10 C. on letter via BARRANQUIL / 29 III 1929 to Berlin (Image)