Excellent shot. It looks like Canon/Nikon ltm's start to be popular with Leica MM users also as Steve Huff published a review today... I first saw Reid's reviews at LL as he was recommending the low contrast lenses for B&W shooting. His review on RD1:
I ended up buying another Canon 50/1.4 in Leica Thread Mount, this time a fairly early V1. This lens was introduced to the world in 1957, same year I was born. I've picked up a number of 1957 lenses this year.
This one is optically perfect, cosmetically almost perfect. You could never tell it was 60 years old. can;t say the same about me!
This is a classic Planar 1-2-2-1 6-element in 4-group lens, the formulation made possible with a high-index of refraction/ low-dispersion glass pioneered by Canon. Unfortunately - that type of glass often reacts badly to oil outgassing onto the surface behind the aperture blades. This one is perfect, some were lucky. Be sure to have inspection and return privilege for this lens when buying.
The Canon 50/1.4 uses 48mm filters, like many Canon cameras and lenses of the 1950s through to the early 1980s. Not a common size, but not too hard to find on Ebay.