440: Rebuild, Replace, or Sell

i'd rebuild it
Any idea of what it "should" cost? Both a typical rebuild and one where machine work would be needed?

I would keep the car.
It looks like its in great shape??
The car is very solid minus the "removal of the inner fenders and replacement with sheet metal." Seems to be undercoated as well. Only real rust is a tiny bit on a lower wheel well or two.