1919 2c carmine rose, used on piece, v.f., with newspaper clipping about Knox Martin, the pilot who flew from Barranquilla to Puerto Colombia, cat. $1200 (Cat No. C1) (Image)

Cat. $1200, Est.US$350

1920 10c Flier in Plane Watching Biplane, unused without gum as issued, large margins all around, rich colors, fresh and fine, pencil signed. Only 53 unused examples have been recorded, cat. $4500 (Cat No. C5) (Image)

Cat. $4500, Est.US$1,500

1921 30c on 50c green, violet surcharge, unused without gum, thin, fine appearance, signed Rendon, cat. $925 (Cat No. C20) (Image)

Cat. $925, Est.US$250

1921 30c on 50c green, double overprint in black, inverted, h.r., some gum toning, fine and rare stamp, signed Oriol (Cat No. C20var) (Image)

Est.US$500