[Bruce Lancaster]

Hard to be sure with all the damage and rust, but it looks like the builder did a decent job on the tin work if not the aesthetics...some of it must have been pretty involved, like the windshield area. The seams between regular Ford and alien tin seem, within the limits of the photos, to be invisible.
My guess...he'd had enough of trying to back up with the original rear window. After he fixed that, he caught rabies or something...