Very nice! The Industar-26 is a Tessar clone, which sounds unremarkable, but every so often one turns up that just Has It with regard to tonality---it looks like you got a winner here!
To what are you referring? Soviet quality control was definitely lacking, so there's a lot of sample-to-sample variability in overall quality. This is of course exacerbated by the age of a FED 2.
You'll see reports from time to time of a need to calibrate each lens/camera pair for accurate focus on FSU Leica clones; however, AFAIK this only applies to the earliest samples (early FED 1s). There was much better standardization by the time the FED 2 came out. Compatibility with non-Soviet lenses is another matter -- such pairings usually work OK, but sometimes you'll run into problems.
The Fed 2 is a nice camera. There are tons of varieties; you could have a dozen and no two could be the same, if you get the right dozen. The factory was constantly tweaking them. Mine is a 2b.