[BRENT in 10-uh-C]

Actually, I feel those shells are indeed repairable however you are going to need to build some specialty tooling, and study up on the principles of metal straightening.

To begin with, you need to fabricate a post dolly stand with a couple of anvils made out of Grade 8 one-inch bolts. I don't believe it needs to be elaborate, and something that can be clamped into a large vise would work well. The heads of the bolts need to be spun in a lathe to the radii shape of the different areas inside of the headlight shell. Then the heads of these anvils need to be polished. The key to these anvils is mass. Next you need a Jewler's Chasing hammer with a polished face, --and you need to fabricate a small slapping hammer out of an old Model-A spring.

Next you need to understand how to shrink metal without inducing warpage. This is more artform than science, but you need to understand that a dent or a crease is stretched metal, and just 'pounding it out' from the inside is doing nothing more that rearranging the shape. In reality, you will have a wrinkled bucket shell. Using the slapper or hammer on the outside while having anvil on the inside is the proper method. You do not want to use a 'hammer on-dolly' method, but instead use an 'off-dolly' method to raise the damage as you strike around the damage with a glancing or sweeping blow. This creates friction which will help shrink the damage. You will also need to manually heat-shrink the metal however you need to be able to control the heat to concentrate it to a precise area. A small shrinking disc for the 4½" grinder would work well if it is well lubricated with bar soap. From there it is just labor intensive progress at a slow pace to correct the damage. Once you are close, then using a fat Sharpie to blackout an area followed by lightly sanding with a blocking pad will show the imperfections.

I could go on further as this is not a simple process that can be explained in 100 words or less however this should get you started.