Are you restoring it or do you want to sporterize it? If you are restoring it soak it in a good paint remover and scrub it with fine steal wool, once you have it clean a hot iron and damp cloth will lift out some of the smaller dents and dings. Try to sand as little as possible with very fine paper 300 grit or finer. Minwax makes a wipe on poly that works good, the more coats the more shine. Don't forget to coat the inside to seal it.
If you want to sporterize it, go out and get a walnut plank and start from scratch. I made a realy nice thumb-hole stock for a Arisaka 99 that I got for under a $100 because someone had already butchered the original stock