I would like to share this not-so-official "Semi-Official" with everyone. This stamp commemorates the 50th Anniversary of Air Mail by honoring the flight of Elliot-Fairchild Air Transport's first company flight from Haileybury Ont. to Rouyn Que. Marking the first day of use of CL#10.
The commemorative stamp was allowed to grace the back of the covers that flew the anniversary flight and were officially stamped by Canada Post
. So, although not given the honor of a semi-official status in references, they had their moment of fame during the flight. Perhaps one day, they will have that status.
I picked up two blocks of four, two singles and also some progressive proofs of these stamps.