Good questions. People have provided good info on what an all matching SVT40 would look like, but I do not think many are out there. The early import SA (Finn) captures are close, but most are not 100% matching.
I know in the US and France a few all matching SVT's have turned up that were captured off German soldiers, but again this is very rare.
The rifles were originally supposed to be issued with 3x mags, bayonet, one mag pouch, sling with 1-2 cleaning kits per squad.
Some bayonets were converted and many were sold to surplus dealers independent of the rifles. The odd time original cleaning kits in the cloth pouch turn up and same with the mags. Usually there were 1-2 stock wrenches and 1-2 gas tools imported in the bottom of the SVT crates recently imported. Usually they were kept by the dealers, only P&D and West Rifle sold them customers that I know of. Where did all the original mags go? I have no idea. Even the mag pouches/slings that come with the rifles are post war and not original to the SVT. You can find original SVT slings in Europe and the odd dealer in the US has some as well.