Rightly or wrongly, I was given to believe that the Soviet versions of German cameras were really hit-or-miss, in terms of quality, and that as years went by and machinery and dies became increasingly worn, the quality fell-off even more.
With that in mind, if one buys an FSU camera today you might get "one of the better ones" that works acceptably, or you might get one that was a dog to start with, and may or may not be able to be improved.
Presumably the odds of "getting a good one" are better with Leitz equipment?
And it is entirely possible that I have absorbed western capitalist bias and some Leica snobbery.
I agree that ANY mechanical camera that is more than say 10 years old, or 10 years out from its last CLA probably needs attention. Maybe five years is more accurate.
To date, I have seven Barnack bodies ( II, III (x3), III-c stepper, III-c/f ST, III-f BD, and only one has turned-up non-functional: my 1951 III-f: cosmetically very nice, but the shutter curtains are crackly and like a sieve. All deserve a CLA, but they all still function reasonably well.
What was the nature of your III-c's failure ?
LF