We won’t go deep into the weeds on what you can find here. Notes of a Soviet Armorer is an occasionally-updated (last in March) detailed review of aspects of historical Soviet weapons, especially the weapons of the Great Patriotic War. He takes information from Soviet-era archival sources, and Russian-language firearms forums, and posts rare but in-depth examinations of Soviet small arms questions.
We could go into greater depth, but we’ll just refer you to his post on Tokarev SVT sniper rifles, which includes serial number lists and production counts. Most “SVT snipers” in the USA or here in the West in general are fakes and forgeries, so it’s worthwhile to see what Russian sources say about these rare firearms. (The rifle and scope are relatively common. The mount? Vast majority out there are fake). He also has a post with entire photo galleries of real period photos of snipers armed with these elegant sniper rifles.
If that’s not enough for you, here’s a comprehensive examination of Soviet-era ammo pouches as used with the SVT and Mosin-Nagant rifles.
Good stuff. If you collect Russian stuff, maybe priceless.