Re: new toy
Look on the flat area on the receiver (under your chamber). There will be markings there that will indicate when it was made, at least from 1949 and on. A circle, a few letters, etc. Serial numbers weren't required till 68 or 69, and only a few used them until then. I wouldn't say you made a steal of a deal, but you didn't get ripped off, in that condition. Most of the singles you find of Stevens/Savage were never worth much of a price, but they were very good, reliable, and dependable shotguns. Can't go wrong with them in my opinion.
There is a fine line between paranoid and prepared.