Thick, are you going to attempt this without the use of bondo, doing real metal straightening? If so, I would like to suggest getting a set of old school body hammers and dollies, an adjustable vixen file, making a "slapping file" out of a coarse tooth metal file and practice on some scraps with all of these tools.
The dents you are working with can definitely be repaired to perfection without bondo, but body metal is very thin and easily damaged. The slide hammer methods do a lot of damage that can be filled in with bondo if that is your intention. If you do not intend to use bondo, skillful bumping from the inside with a dolly and filing with the vixen to find the low spots then bumping from the inside with a pick hammer to bring up the remaining low spots will get 'er done.
You will be able to feel irregularaties in the contours with the palm of your hand if you place a thin piece of cloth between your hand and the metal and you will be able to see subtle irregularaties in the dim light of dawn and dusk.
