Thanks Phosphorus, Carl's. I don't know that much would have changed with Soviet manufacture and rework methods, marking and numbering in the 10 years after 1945. If it's refinished if blued it would be buffed, or painted/coated, or simply dipped. A nice polished blue finish would smooth and buff out more of the "ridges" around the numbers caused by the die strike metal displacement.
Even with WW2 MNs it's sometimes tough to tell the extent of the rework. Again, exceptional site and thank you for the guidance.
Regards
HB