Is this fixable

Don't let the fact that the other is not a GT hold you up.....I think basically the only difference in the GT model is the body side molding and the front and maybe rear bumper? which some of that should still be good on the car you already have......and there may be something different with the GT engine? but if so....you have that too!......maybe the wheels to? I think the GT's had chrome wheels.

As for the sun roof.....yank it out of the car and set it aside until you can work up the cash to have someone install it in the donar car...or do it yourself.

just some ideas