Reference

The thing with reference books is that they're not all encompassing.

The jacket is definitely Canadian -- even without the tags. The wool lining is identical to that used on late war flying helmets (a type not seen in most books). The lining is the same as used on RCAF Deacon Suits -- a 2-piece flying suit also not seen in books.

By color, almost assuredly not RCAF. Which leaves RCN and Army. It looks like the top half of a Pixie suit and decidedly unlike any naval uniforms I've seen.

I would venture that a look at Canadian tank uniforms of the late 40s/early 1950s will yield some clues.