I'm aware of most of these issues. I put my small tools to use from time to time just to keep things operational. Yeah, the metallurgy isn't the best, but optically, they are visually as good as the Elmar.
Biogon44 wrote:
Hell Bob,
I also have this Soviet lens. They are good optically, but suffer from defects in metal technology and assembly. I once had a 1000mm f11 Soviet-made M42 fit mirror lens (later stolen) with the lettering ‘Made in USSR’ applied crookedly. Typically their lenses need re-tightening of screws and cosmetic touch-up of painted areas, in addition to checking their mechanical functioning. All these measures must be taken prior to shooting pictures with them.