1930 5c Air Mail Die Essay in Black, mounted on thick card, with the word "POST" at right instead of "POSTAGE". Very fine and quite rare, with pencil note on back reading "ex. John C. Cornelius", accompanied by a 2018 Greene Foundation certificate. (Image)

Est $ 3,500

1930 5c Olive Brown Air Mail, a mint never hinged plate 1 block of six, showing the reversed 1 in the left margin, middle row, fine-very fine. Only one of these appeared in every sheet of 200, in the upper left pane of 50. Some sheets had wide margins and some narrower, and we are aware of only 3 plate blocks of 6, with only one having a wide margin, as many of the plate sheets were overprinted for the Imperial Economic Conference issue. (See also Lot 798). (Image)

Unitrade $ 1,662

1935 6c Air Mail Photographic Proof, of the final design, enlarged (to 57 x 40 mm) and mounted on thick card. There is a circular handstamp on back reading "Philatelic Sect., Fin. Br. / P.O. Dept, Ottawa. FEB 8 1936". A recent RPSC exhibit of the 1935 Pictorial Issue did not include an example of this photographic proof. Accompanied by a 2018 Greene Foundation certificate. (Image)

Est $ 650