Canada 270

1946 (14c) Hydroelectric Station, progressive large die proof in black without value tablets on india paper 72 x 62mm, sunk on full-size card 227 x 152mm; without die number or imprint.

A spectacular and extremely rare proof ideal for an advanced collection, XF
(Unitrade 270 progressive proof; Minuse & Pratt 270PX-Aa)