An English wheel used improperly in this scenario may add stretch to the equation. Given the dings and dents you already have, the panel is already stretched at each of these spots, and will need shrinking more than anything. You can use an English wheel to wash over the walnuts, and can be used effectively, but you will need to have minimal pressure and the anvil closely matched to the underside of the panel to lessen any chance of changing the shape. This may involve many changeouts to different radius anvils.
I would suggest checking Amazon or other sources for "The Key to Metal Bumping" to learn off-dolly hammer work. It's a very old book, but a very good resource. A good online source is available via Uncle, here:
http://www.hnsa.org/doc/pdf/metal-body-repair.pdf Another useful tool is a donut dolly that allows off-dolly repairs but the support at more than one point tends to be more effective.
Here on a flat aluminum door skin:
http://www.garagejournal.com/forum/showpost.php?p=1843066&postcount=247 ...here on a simulated roof damage....
http://www.garagejournal.com/forum/showpost.php?p=1638725&postcount=235 ....and here on sandblast damage (My theory on measuring was an inaccurate assumption, so be sure to read this one in entirety for the "true story".... This thread also shows good use of a stud puller with shrinking tip.
http://www.garagejournal.com/forum/showthread.php?t=132084 
