I think the Manufrance guns can be accurately dated from the model number. I’m not the guy who can do that, however. My suggestion would be light loads, none of those 1 1/4 Oz 16 gauge things they sell, and I would expect it will be a wonderful little bird gun. Looks to have been choked mod and full when it was new.
Is the retractable sling still present in the butt stock? Not my favorite French sling, but, handy if you need to free up your hands to work the dog, or if you have called it a day, hopefully with a brace in the bag, and need to walk back to the truck.