silver could work. i believe silver is a lot softer though, but with the rough texture, it should age nicely even when it gets banged up. worst case scenario, can always use it to kill vampires and werewolves
i'm very excited about this. if you come up with precise measurements for a case in silver, i'm definitely purchasing.
I still urge you to consider just replacing the entire housing assembly though
edit: considering you have all of the corners covered, as well as the curvature of the back integrated into your "web" design, it wouldn't be out of the question to create a fully covered back, would it?