Phak 1 The lead body man I was around 52 years ago would heat a red place about like a quarter then back it with a flat dolly then pound it with a FLAT round body hammer about 1 1/2 inch in diameter.
When I went to Auto Body trade school (a mere 54 years ago, I was taught to heat up a spot cherry red about the size if a dime and hammer and dolly around the spot working the metal into the center, then quench it with a rag dipped in water. That was for extreme stretches, and in Kevin case, I think that would do more harm than good.
