Thanks Jim for all your help and answers, this will get me a step closer to figuring out what I really have. When I bought this I didn't realise it had the sunken rib on it. I guess I got in a hurry to buy it before someone else snapped it up.
As you can see from the pictures of the auction, the stock needs to be refinished and there is one dent that I will have to lift out of the barrels. Lucky for me I have a 12 gauge dent lifter. Other than those things, it seems to be in perfect working order. The fact that the safety doesn't reset itself bothers me some. I'll have to open her up and see what's going on there. Bob