Purchase value and refreshened value are two different things. This is what I call a 10 if gun. There are about 10 things on this gun that you could look at for value.And if yes or no is the answer it changes the value of the gun. If all ten were yes then the gun cuiold be restored to the top figure value of $2,000.00. It might cost you two thirds or more of that to get ther work done. If the answerw are mostly no then the gun is scrap and worht just a few hunder.
1 barrels or bores pitted
2 ribs tight
3 both barrels fit properly with the forend
4 any cracks in the stock
5 is the straight stock a converted pistol grip stock and is it well done if so.
6 any external pitting or dents in the barrels
7 is the stock oil soaked
8 is the gun on face
9 other than the external rust has the gun been cared for well
10 do you like the gun as is if refinished or are you looking for a higher grade gun and just willing to settle for this one.
If you can answer all of these question and find that the gun is a solid gun with just a few surface problems buy the gun. But if you intend to have it refinished by others you ought to get a ball park figure what that will cost and deduct that from the price as best you can. Not telling you to steal the gun but do not pay $1,500.00 for a gun that you may end up with $2,500-3,000.00 in before you are done.