You have gotten some very good advice. First off buy your self some Aero kroil penetrate. It is the absolute best and is great at removeing the film from long storage. Second up in Maggee Valley, NC there is a motorcycle museum Wheels Thru Time. I would contact them and maybe arrange to take the bike up there for them to look at. They have a lot of hands on experience and love to see barn finds. Keeping it stock is great but seriously consider converting it to 12 volt for ease of starting, etc.