Salvation Army Centenary in Canada. The centenary stamp was  issued 25.06.1982. This is a plain cover, addressed to the Salvation Army, Red Shield Campaign Office in Ottawa with a local PM: the Ottawa Postal Museum. It is unlisted in the SA FDC catalogue. Not seen before. Information on the SA Historical & Philatelic Association FB site (Rob Kerr): It was likely issued by the Public Relations and Development office for that region. This envelope would have been the standard door to door Red Shield Campaign envelope. I don’t recall them being provided with postage affixed. Likely someone took the envelope and affixed the postage and had it cancelled at the postage museum in Ottawa.