Find a local Harbor Freight Tools and buy the 1/2 football shaped auto body dolly. They are like $15, sometimes you can get both it and the teardrop shape dolly on sale for less than $30. Also while your there, pick up an auto body flattening hammer. It'll have a big flat round face about the size of a 50 cent piece, and a small deep peen on the back. Should have a red/black handle. Those sell for I think $10 or less.
Use that auto body dolly in a vice with the flattening hammer to get all those dents out. It will be a night and day difference you can use over and over again for minimal investment.