While i frequent 7.62x54.net all the time, it is mostly focused on Mosin Nagant rifles. I recently came across this gem today with a whole slew of excellent information and pictures documenting further the various proof marks and acceptance marks for many of the soviet weapons produced in and around WW2 and thought id share:
https://www.m9130.info/
The "reference section" tab at the top is where you will find the breakdown for everything
https://www.m9130.info/
The "reference section" tab at the top is where you will find the breakdown for everything