If you can find one of these hail-chaser guys I'm sure he can do it. They use long rods for leverage to push out dents (caused by hail storms) and get it darn near perfect. They travel, following the storms, but I know there is one based in the Poconos.
They shine a light on the outside of the tank and move the metal in small increments until it is perfect. It is an acquired art and there is a school for it in the south somewhere. He saw and fixed dents in my Eclipse that I didn't even know were there. (Plus the ones I could see!)
Russ