paulfish4570
Veteran
i happened to see one on ebay. photos showed what appeared to be a screw mount of appropriate size. google search did not turn up anything definitive. my helios 44-2 in m42 is a dandy little lens, but because it is preset, does not get much work on my pentax sp1000 when i have an auto super takumar 55/2. a helios in LTM would be a great choice for an fsu or bessa. preset obviously woulkd not be an issue ... 
It is a 5.8cm lens, and was never available as a rangefinder coupled lens. You can find it in 39mm SLR mount, but the back-focus is different.
Brian
Brian
paulfish4570
Veteran
thanks, brian.
vnukov_pk
Established
I have one in m39 screwmount. the flange distance is different from ltm. I use m39-m42 ring to mount helios on fujica 801 m42 camera. The results are very nice, old lens is way better than new mc version.