Thank you for this. I have watched a couple comparisons between these two lenses and yours is the best so far! Great job getting into the detailed differences between the two.
These are great lenses. I prefer 44m, I have one adapted for Nikon. More practical ergonomics. Also there's fresh alternative from Meyer Optik Gorlitz Biotar 58 f1.5 II for 1200euro
The early lenses were made in small quantities in the KMZ factory. Valdai opened in the 70s and the build quality dropped because production had been scaled up.