I don't know what level of restoration you are aiming for, but with the great expanse of virtually unsupported sheet metal, it will be exceedingly difficult to make that panel perfectly straight. Not impossible, but very time consuming for even a professional tin smith. I have attempted it on one and had to come to grips with my inadequacies, got it as close as I could and rolled on Herculiner bed liner. It hides my imperfections nicely. Not everyone's cup of tea, but I drink coffee.
Carl
