Not much info about this lens on the net... Any good lens, or average performance? Wonder if it is a standard m39 mount, fitting both leica and fed/other russians. I searched ebay, no hits for this lens, only the faster siblings.
It should rate as an average performer for it's type in the mid to late 1950's, it was the standard lens for Canon, unless a high speed 50mm version was bought. I doubt if it was worst than an Elmar or Tessar, it should be better or on a par. It should fit Leica OK.
Not that common in the UK, usually the faster standard lenses turn up. There was no official importing of the early Canon cameras or lenses till about 1959 or so.