Early Barracuda body cracks under rear window

Pishta, When we discussed it yesterday he (my body man) said it is like getting the solder off of a copper pipe once its on there. I've done a lot of copper work and I can relate, but steel isn't copper, so evidently it is possible, as Bodyperson above indicates. Its worth a try to eliminate the cracking from coming back after I pay $$$$$$ for the body and paint work.