Ironically, in spite of all of this, I think that car has pretty decent potential (except for that poor grille). It has good interior color, buckets/console, the cool 3-spoke steering wheel, just needs some dye in spots. And it's important to note that nobody questioned the legitimacy of the mileage.
The underside may not be pretty, but none of us would drive it in the snow or rain, so it's not going to get any worse. The surface rust on the bottom of the body wouldn't really require full-blown pro paintwork, and all the other $$/work it might need is to be expected for a car this age/sitting so long. Not really any surprises there, if you think about it - expect to go thru tip/tail replacing all 'spoilable' items. When you're done you have a reliable 16k-mile car. Enjoy it for 5 years, you could put 20k more miles on it even, and you'd still have a low mileage car, and one that's road-ready - I don't think you'd lose much money at sale time.
I don't think we'd find a better low-mileage example around for less than $4500, I think anything preserved to the 'perfection' we want is going to have a 10k asking price. People that have those cars tend to ask big $$$. And at that point I think we'd all be balking at 10k for a non-collectible 70s car (I would, anyway).