Series "1" imperforate pane on white ungummed paper, showing trial colour of the FRAME ONLY, along with Style Two airmail inscriptions in violet; couple light bends at foot of no importance for this one-of-a-kind proof pane, VF (Unitrade CL18 Frame) (Image)

Estimate 3000 $

Series "1" imperforate pane on greenish blue gummed paper, showing proof of the FRAME in dark violet, inscriptions at sides, colour and paper are same as the issued Style Two; small area of gum disturbance on one and crease in left margin. Annotated "First Proof June 26 / 26" in pen at lower right. A fabulous and UNIQUE proof, VF (Unitrade CL18 Frame) (Image)

Estimate 3000 $

A similar lot, but with trial colour of the FRAME in violet, inscriptions at sides; small spot of gum disturbance on one. A striking and UNIQUE pane, VF (Image)

Estimate 3000 $

Series "1" imperforate pane, dark violet frame, airplane and route inscriptions in orange, showing "OTT" in "LOOKOTT" variety (Pos 4); without marginal inscriptions and printed on white ungummed paper, VF (Unitrade CL18Pi; cat. $4,400+ for normal proof singles) (Image)

Estimate 2000 $

A similar lot, VF (Image)

Estimate 2000 $