1924 (25c) Laurentide Air Service Ltd. mint booklet pane of two, with glassine interleaving still adhered to gum, still very fine. (Image)

Unitrade $ 325

1924 (25c) Laurentide Air Service Ltd. mint booklet pane of two, with glassine interleaving still adhered to gum, still very fine. Includes its unattached front and back cover, the back being blank. (Image)

Unitrade $ 325

1924 (25c) Laurentide Air Service Ltd. mint booklet pane of two, with glassine interleaving still adhered to gum, still very fine. (Image)

Unitrade $ 325

1924 (25c) green Laurentide Air Service, Second Issue, rouletted at top and bottom, with booklet selvedge at top (with holes from two staples), mint lightly hinged, with a stain, else very fine. (Image)

Unitrade $ 160

1924 (25c) Laurentide Air Service Ltd. complete booklet, with four panes of 2, each pane having its glassine interleaving adhered to the gum. The back cover has the designer and printer information printed on it. Light staple rusting, still very fine and seldom seen. (Image)

Unitrade $ 2,000

1924 (25c) dark blue green Laurentide Air Service Ltd, from the third issue, mint never hinged, fine. (Image)

Unitrade $ 300

1924 (25c) red Laurentide Air Complete Booklet, with bottom stamp of each pane a lighter red, all panes and inter-leaving are intact, very fine. (Image)

Unitrade $ 3,000

1926 (25c) Jack V. Elliot Air Service Semi Official Airmail, in a mint never hinged full pane of eight. Quite fresh and very fine. (Image)

Unitrade $ 900

Group of 17 Different Mint Semi-Official Air Mail issues, all on a black stock sheet, with CL6, 8c, 9, 10, 13, 41-52. Seven stamps are never hinged, most are fine or better. (Image)

Unitrade $ 1,180

1926 (25c) Jack V. Elliot Air Service Semi Official Airmail, in a mint never hinged full pane of eight, with a "white spot" on stamp in position 8. Quite fresh and very fine. (Image)

Unitrade $ 900

1926 (25c) Elliot-Fairchild Air Service Semi Official Airmail, in a mint never hinged full pane of eight, including two "tall R" varieties in position 2 and 4. Quite fresh and very fine. (Image)

Unitrade $ 675

1926-27 (25c) Patricia Airways Imperforate Proof, in a mint never hinged full pane of eight, Plate 4 in green, on white paper. Stamp designs have no inscriptions or airplane, etc. Marginal inscriptions include (on both sides of pane) "ED AKE". Bottom margin has a light pencil notation "First printing of Red Lake". Very fine, fresh and quite rare (Image)

Unitrade $ 5,000

1926-27 5c Patricia Airways with Type B Overprint in Green, Descending, with third O in LOOKOUT malformed in position 7, in a mint never hinged full pane of eight. Fresh, very fine and rare. (Image)

Unitrade $ 1,425

1926-27 5c Patricia Airways with Type C Overprint in Red, in a mint never hinged full pane of eight. Fresh, very fine and scarce. (Image)

Unitrade $ 1,440

1926-27 (5c) Patricia Airways with Type D Overprint in Black, Inverted and Descending, in a mint never hinged full pane of eight. Fresh, very fine and quite rare. (Image)

Unitrade $ 2,400

1928 (5c) Patricia Airways Overprinted RED LAKE in Purple (Inverted) on Cover, mailed Red Lake (MAR.19.1928) and addressed to Liverpool, England. The semi-official, which is properly tied, has a purple overprint, and inverted, unlisted as such in Unitrade. Rare and very fine. (Image)

Est. $ 500

1929-30 (10c) Commercial Airways Imperforate Proof, top marginal pair, in black ink on white ungummed card with large margins. The right stamp shows the "broken C variety in position 2" variety. Very fine and scarce. Ex. D. Sessions with two "Kessler" handstamps on back. (Image)

Unitrade $ 900

1929-30 (10c) Commercial Airways Imperforate Proof, top marginal pair, in purple ink on white ungummed card with large margins. The right stamp shows the "broken C variety in position 2" variety. Very fine and scarce. Ex. D. Sessions with two "Kessler" handstamps on back. (Image)

Unitrade $ 900

1928 25c Klondike Airways on Roessler Cover, mailed Mayo Landing, Yukon on NOV.29.1928 to East Orange, New Jersey, with Jan 1929 New York machine transit cancelling stamps, very fine. (Image)

Unitrade $ 450