Haileybury-Rouyn - "Cinderella" MNHOG Block of 4 - "semi-official" 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.