I have one of these, which I occasionally use on a FED-S from 1941. This lens and this camera were made before the lens-flange-to-film distance was standardized, and on my camera everything lines up properly. I guess it was matched to the camera as I bought the camera, its Summar copy 50mm f2 lens and the 100 in one batch. When used on a camera with a standardized flange distance the RF and the distance engravings don't quite match, and the infinity mark is nowhere near the top where it belongs. This could be fixed by shimming the lens flange, I guess, but I prefer to just use it with the old FED. At f6.3, though, this lens is so slow that I doubt that you would see much of a focus error in any case.
I haven't been very rigorous about it, and have only made a few exposures. It appears to be fairly sharp, but the contrast of this uncoated lens is not so hot. Unless you are wanting to be really authentic with your Russian gear, you are much better off with a nice old Elmar 90 f4.
Cheers,
Dez