That is a 1970 model. You need to take stock and forearm off as well as look at the recoil pad screws. and carefully look for some corrosion evidence.
Art performed a lot of restoration work after the crap hit the fan on Salt wood. If, for example he did the work, the end result is 'new gun/good wood' and it will raise the price of the Superposed in that price range. THERE WERE A LOT of CLEAN 68-70 guns and yours probably is one of them
I sold a 1965 in 99-100% two months ago with 28" bbls, nice wood, briley chokes for $3200 and a 1969 99-100% original-no rework 28" IC/M for $2400 - every bit as nice as the 1965 - but it was in the 'bad range' which spooks the guys knowledgable about Brownings. Additionally, 26 1/2 barrels always bring a lower price, condition same otherwise..
You should consider keeping the price at $2200 range if you can afford to hang on to it, but you need to remove stock and forearm and take picks of the action and forend to demonstrate 'clean'. If rust/corrosion evident, you will be down in $1300-1800 range despite the excellent appearance.
Take what you want and leave the rest.