Well the shotgun had been sitting in a garage in the open, next to the backdoor with all the drafts for at least 40yrs. I found some 150grit aluminum oxide sandpaper at the house and soaked it in water, then wet sanded it very lightly. It smoothed out the barrel and reciever very nicely. I oiled it down and I took some wood polish and used it on the stock. Thats all I did and it turned out great. I took a chance using that grit and I wouldnt recommend it, but it worked in my instance.
Surprisingly, there were no major rust issues with the gun. There was spotted surface rust and little 1 inch spot on the barrel but nothing too crazy and it came off nicely. I'm probably getting a parts kit for it in a couple days and hopefully have it in working condition by next week.