Excellent find! And a fair price... I don't think either party should be crying here. Sales of the small "collector" bikes have been down, but at the same time original ones are harder and harder to find, with the advent of these shows like Pawn Stars and 'Pickers.
The bike looks very original, correct as you called it on grips and rear tire. A repro RWL Stingray slik will look perfect on there... unless you can really find a "pie-crust" slik... good luck. Nothing wrong with using a nice repop.
The grips exist out there somewhere... probably find them for $20-25. The chrome all looks very saveable. Seat looks great. BE CAREFUL with the seat- they can and do crack in the widest part of the curve, and it's awfully disappointing... ask me how I know.
The grey cable sheath can be found to redo the cables- and fortunately pieces like the clamps and overload tube are there. The fork truss rods are slightly bent, but those should straighten out fine. A new chain will complete the bike- if you can get one from a Collegiate, so much the better, it'll be the right SEDIS chain, if you're concerned about such things. Any 3/32 derailleur chain will work fine and KMC's seem to work great for me.
As for the chainguard screen, I'd just buy a black decal and apply the STING-RAY part of it, then clearcoat the whole thing very lightly after it's been dry for a week... beyond that I wouldn't touch it.
I figure you know most of this stuff but I like to put it out there so others can learn about these legendary bikes too. Have fun with it!
--Rob