I believe I stumbled upon a '68 or '69 Belvedere...

IMHO, it's a parts car.
To replace the roof and well.......90% of the body panels including the floor and probably the trunk floor as well, will cost you a fortune and a lot of time.
With no drive train other than the diff, that's a lot of money too.
Did you find the V.I.N. on the dash? If it's gone, that's a deal breaker right there.
It's on the driver's side easily viewed through the windshield (if it had one lol).
You would be into the car for at least 60 grand and it would be worth about 30 grand when done.
If you want to fix it to save it, that's up to you.
For my money, you could find a better car to restore and use this one as parts.........
But for 200 bucks, i would get it and see what can be salvaged.
I am typically a ''saver'', but this one is too far gone even for me.
I was wrong, the color appears to be the right one, F5 Medium green metallic.
But the vinyl roof and the paint color underneath it has me suspicious.