But, if you want to customize it (and are not concerned about a warranty), you could always take the plastic case apart, and rough sand it and smooth it, and then hit the shell with a nice base coat and then a nice coat of metallic paint of your choice. Then, clear coat, and let dry.
If you're not into that much custom work, then I'd just forget it. Any attempt to use the aluminum case would only require more alteration and skill than. It could be done, but you'd have to spend some time custom fabricating filler pieces and such.