1) Depends on what you're looking for. Generally, as long as it has nothing to do with Globe arms it should be fine, but the rarities to look out for are if it was made prior to 1940, as these are SVT-38s, and a bit rarer, if it has rails AND a notch out of the back of the receiver, as these are sniper variants (many models have just the rails, they need a notch out of the back of the receiver too), and if they were made in the Kovrov arsenal, as only about 50,000 rifles were made in the Kovrov arsenal. Other than that, the usual rust/pitting, and matching numbers. When they refurbished these, they'd often zombify them, and electro-pencil matching numbers on them. If they're stamped matching, that's a lot better. Sometimes, they'd also replace the original stock with an AVT-40 stock, it has a large A burned into it and a second notch around the safety, to accommodate the full-auto selector in the safety. Putting these on was a fairly common refurbishment procedure. Another thing is the plum versus silver bolt, plum means refurbished, silver means it was a war bring-back and a bit rarer. Don;t expect even a pencil-matched magazine, almost none of the mags for these match, pencil or stamp. Some people/companies would cut the 10-round mags to 5 to make them legal here, these are often flimsy and they're a disgrace to own, so get one with a rivet in it, not cut.
2) Clean the cosmoline off, it's everywhere. It may not look like it, but it's in the gas system, the bolt, the magazine mechanism, everywhere. If even a bit of it is still there, it can cause issues in cold weather with the bolt being held open with a full mag because the mechanism that holds it open, activated by the mag, is frozen open, and the firing pin or trigger spring could freeze up, and you'll get a light primer strike, and the round won't go off. It'll usually go off the second time it's struck, but that *click* when you're expecting a *bang* is disconcerting. Make sure you set your gas setting right, most people tend to have theirs on 1.3 or 1.5, if you don't have it up enough, it won't cycle. Make sure after you're done adjusting it to tighten it so it doesn't slip to a different setting. There's a ring that the rod fits into, that ring loosens and tightens, you loosen the ring to be able to easily change the gas setting, which is done by turning the 5-headed bolt on the front of the gun, above the barrel, to the face with the right number on it, and tighten this ring so that bolt won't move, and will stay on the right setting.
Don't expect MOA accuracy, it's Russian surplus, be happy you can hit an 8.5x11 target at 100m. If it's not perfectly aligned for you, the front sight adjusts much like a Mosin's, and if it's shooting too low/high, you have to either add to or subtract from the front sight, it's not very adjustable. There is the alignment mark on the barrel and the sight post for a rough sighting in, the Russians marked almost all their guns like this when they had them "zeroed," getting the notches lined up on the barrel and sight post is the easiest way to sight one of these if it's off.
3) The corrosive stuff is dirtier than a cheap hooker, the thing will need a thorough cleaning all over after firing it, receiver, mag, chamber, barrel, and gas system. The barrel's top near the gas system and the rod that goes in the gas nozzle will need to be wiped down to get the powder and salt off them. The easiest way to clean the gas port is with a pipe cleaner (like the kid's craft thing, the fuzzy metal wire) dipped in oil. The cleaning rod it comes with isn't long enough to fit down the whole barrel when cleaning it from only the rear, through the receiver, so clean it down the front too, or use a longer rod. Make sure to wipe off the powder from the muzzle break too.
