i went to check out the mosin at big 5 sporting goods....the outside looked like it was in decent condition but the manager working there wouldnt let me take apart the bolt to look down the bore. from what i could tell there was a lot of gunk on the bore...like dirty oily stuff. and there were some rust pits that i could see. i kinda decided it wasnt worth it. the rifling was still decently strong from the looks of it...but there was a decent amount of rust that i dont want to try and fix.
edit. i should also note that the rust wasnt just in the bore, it was on the muzzle of the gun as well. it was made in 1939 and the factory marking was a star with an arrow in the middle.....that looked like this.