Hopefully one day Gollevainen will have enough time to finally compile full and up-to-date Russian Parts Sheet, but until then, You just need to ask for the needed parts on a case-by-case basis, and He will either send You new parts, or tell You to use the ones from the Sheet (if they're still correct, or nothing more new is done).
I hope that the new Russian parts sheet is made as comprehensive as the US and British parts sheets, with seperate sheets for weapons and radars.