H Wally's got it.
An original non-refurb would have worn 60-70 year old bluing, probably turning to patina in places, and little to no shellac left on the stock. Old nagants sometimes look to have an oil finish, but if it is a Russian nagant the shellac has just worn completely off.
You don't see Russian non-refurb nagants here, but looking at a Finnish 1891 or other models will give you a good idea of what one would look like.