Imperforate proof pane showing basic design - no airplane, printed in black on white-surfaced card, ungummed; striking and rare, VF (Unitrade CL43P; cat. $7,200) (Image)

Estimate 2000 $

A similar lot (Image)

Estimate 2000 $

A similar lot (Image)

Estimate 2000 $

Matching top margin imperforate proof pairs printed in dark green on yellow gummed paper: first pair, series "6" without airplane and second pair, series "20" with triple print of the airplane in plum. Both with printer's crayon mark in right column; hinged in margin leaving both pairs VF NH (Unitrade CL43Pii, iv; cat. $5,775) (Image)

Estimate 1000 $

Series "4" rouletted proof pane of eight in dark green on yellow gummed paper - no airplane. Centered left, crayon mark through right column applied by printer, likely due to weak impression. An impressive sheet with full original gum, Fine NH (Unitrade CL43Piii; cat. $9,100) Side margin inscriptions are noticeably weak and the "-PAL-" printed letters on both sides are thinner than those on the issued sheets. (Image)

Estimate 2000 $