Sorry to hear the testing did not work as hoped. Cooler temperatures have a negative impact on mine as well, specifically rear curtain travel times. I've posted in another thread on the topic. I can make the problems mostly go away when I use a space heater to warm up the camera so I'm guessing it's an old lubricant issue. In any case I will have to do a full CLA on mine as well. I bought a Zorki 4 with a bad shutter so I'm using that one to learn. When I feel I comfortable with the procedure and that I can reassemble the mechanisms properly I'll try it on my good Zorki 4. I've had almost no time this week for cameras though. Perhaps this weekend I can make some time.

On the Industar lens are you sure it was re-assembled correctly. I don't understand how it would be worse unless some of the elements are not installed correctly. I took apart an old Cintar lens for my Argus and it took a few tries to get it back working properly again. I remember I had made some re-assembly errors but that was so long ago I don't remember exactly what I had done wrong, elements not seated well or in backwards or something.

You probably already know about this but I found some information on the backsighting method to re-calibrate the focus on my Argus lens after I had it apart and I have used it to verify focus calibration on my Zorkis. I use the second method in the article.