It'll never be cost-effective to restore it, probably well into the future. BUT the worst thing I see (from the pictures) is the instrument panel pad being aged.
MUCH of what's been removed would have to be removed anyway for any rebuilt/restore activities. In that respect, part of that work has already been done.
With the engine/trans being gone, that would be a prime situation for a later model drivedrain. Even an unwanted V-10 and a modern 8-speed, possibly! A RB stroker motor might be interesting, but would probably be a waste with the 8-speed, as the 8-speed has something like a 4.50+ low gear, to me. On the other hand, a modernized B/RB with an 8-speed would be nice. Add a 3.23 or 3.55 rear axle to balance the OD ratios and make it a comfortable highway cruiser for long distances at a time. Even pair it with a vintage Airstream trailer (with appropriate chassis upgrades).
BUT, underbody rust, in addition to the normal Fuselage rust areas, would be the determining factor, to me, plus how much money to fix whatever might be there. Time and money can fix everything, IF somebody might want to make those investments. The rear window rust would be considered "normal" and not really in this mix?
Retrieval and clean-up would be the first steps to seeing what's needed and go from there.
Different ways to look a things.
Enjoy!
CBODY67