Industar 50/3.5

Wrong Forum, I know but thought I might get quicker response here. My question, does anyone have fist hand experience with fully collapsing a FED 50/3.5 ltm lens on a Canon bottom loader? In particular a IVSB2?

IIb for me with a '57 Industar 22. Works together perfectly.

Those who knows are in RF forum. Do you need more quickies or more response with actual knowledge?

50 3.5 collapsible lens with FED label on it is most common as coated after war Industar-10.
Usuall rule of difference between FSU LTM RF and rest of LTM Leica copies will apply.
It is not difficult lens to work on to make it spot on on non FSU bodies.

Here might be rare prewar FED marked collapsible 50 3.5. And just as with earlier Barnacks, lens-camera coupling was individual.

Any of those FED marked should have less possible problems. Thier construction is almost exact as Elmar.
It means if you rotate focus it is less likely to stuck on the camera body on closer to infinity.
And it has shortest tube among collapsible Industars.

Thanks guys. Appreciate your input. I grabbed one on ebay. Kostya, it is a later coated model FED with the more current aperture scale. Your friend (and mine) Swift 1/Colton steered me in the right direction.