Proof  -- 18c. Kingsford Smith progressive proof vertical strip of three showing aviator and plane only (missing black and orange), marginal from the left of the sheet. Photo
Proof -- 18c. Kingsford Smith progressive proof vertical strip of three showing aviator and plane only (missing black and orange), marginal from the left of the sheet. Photo

Details
Proof -- 18c. Kingsford Smith progressive proof vertical strip of three showing aviator and plane only (missing black and orange), marginal from the left of the sheet. Photo