Auto body repair & detailing: 57 chevy got rear ended :-(, acetylene torch, cutoff wheel

Question
My 57 got rear ended and I've got most of the line back where they should be. But I'm having trouble with tightness in the metal in the whole quarter panel. I've been using a shrinking disc to even out spots and I think I might have over shrunk it. It's getting the "oil can" effect. All out of ideas. I don't want to take the whole panel off, but what else can I do?

Answer
Shrinking discs are bad.What you are experiencing is stretched metal.The best way to shrink it back is with an acetylene torch.Heat up an area cherry red about the size of a dime ,hammer around the red area with a dolly on the back side working your way inward and then cool the area with a wet rag.You will want to do this in the center of the oil can.You might have to do this several times until proper firmness is achieved.If the metal is stretched too bad you may have to cut a line in the center of the oilcan and reweld it shut with a mig welder.Only a line about an inch or two with a thin cut off wheel should suffice.When you grind the weld use the cutoff wheel to dress the weld and not heat the panel too much.Any more help let me know and good luck.