I have a guy wanting to trade me a marlin 336 30-30. I dont think it is worth as much as he does, so I wanted to get some opinions. The serial number prefix is 17xxx, that should make it a true Marlin manufacured in 1983, correct? I would rate its condition in good, but not very good. It has typical handling wear and marks, but still funtions 100%. It has some type of peep sight on the rear. Just a rough estimate, how much is it worth?