Are you sure about that? I don't collect Canadian First Flights, but in looking up listings for the cover, the 235o is said to be Medicine Hat to Calgary; the 235w is Medicine Hat to Moose Jaw, which is the cover in question, I believe. The value for an unsigned cover is +/- $5.00 according to this listing:
This is probably the biographical sketch for the W.J. Johnson autograph on the cover (referenced in Archives of Canada):
Quote:Wardin Johnson was born in Teeswater, Ontario, on January 13, 1884, and was educated in Toronto. In 1905, Mr. Johnson came west for a holiday and was so impressed, he decided to stay and make his home in Calgary, Alberta. On September 1, 1905 (the day Alberta became a province) he joined the postal service as a clerk. May 1, 1907, he was transferred to Medicine Hat as Assistant Postmaster. Mr. Johnson later became the local Postmaster in 1928, before his retirement in 1949. Mr. Johnson gave 44 years of service to
Canada Post.
Mr. Johnson was married to Ethel Anne (nee?), who he had a daughter with, Orma. Ethel Anne passed away in 1955. Wardin resided at 522- 3rd Ave SE up until the time of his death.
Wardin John Johnson passed away November 14, 1970, at the age of 86. His funeral service was held at Cook's Funeral Chapel, officiated by Reverend Brian Brown. He was later interred at Hillside Cemetery.