I would see if it is indeed a salt wood stock. You can do like Hawk said and remove the screws in the butt plate to check for rust.
Really just check the normal stuff, cracks in the stock, loose hardware. I would ask to shoot it as well, to make sure there are no issues with the bolt mechanism, firing pin, feeding, trigger and see what kind of groups I got.
If you can get me the serial number, I can get you the date of MFG. The date of MFG is no gaurantee of salt wood but checking the screws will tell the story.
JM
