Well, here we go with the rear end swap.

Uhhhh, the roof in that green car has already been worked on. The fact it’s red means if it was a vinyl top car and the rest of the paint (green) is original paint, the original colour under the top would have been cream/white. That looks like filler with some red primer that been sprayed on it many years after the car was made.

It’s a ‘74+ based on the front upper seat belt anchors.

Exactly.
And a pretty nasty job of it at that.:D