Clean it up with oil. Wipe it down well every day for a couple of weeks. You would be surprised how well that alone will work.
Oil all of the action parts well, and let it soak in for a few days. See if the action will work. If it does call it good. I would not try to make a shooter out of it. The condition is a good proof of its authenticity. Many of the old ones have patina.
I would clean it up. Make a display box for it with some memorabillia in with it, and make it a real cool wall hanger.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.