For a FAR tougher and more chip-resistant finish, go to http://www.lauerweaponry.com/,
get one of the "Shake 'N Spray" kits, and apply two or three coats of Duracoat.

Duracoat is normally applied to small machinery and firearms destined for severe field service (such as in Iraq and Afghanistan), and I believe it's as near bulletproof as anything you can apply at home. Airbrushing used to be required and is still a good idea, but they now have a spray can kit (albeit a bit expensive) if you don't have an airbrush and compressor. Worth every penny IMHO, I've used it on several items in the past few years that are subjected to rough service, including a large Gitzo tripod, several cameras, and other small tools and machinery. Great stuff. Can be cured by gently baking in your wife's oven, or air-cured--although full air-cure can take several days to several weeks, depending on humidity and temp.

Here's a photo of a Leica M2 I restored. Stripped to bare brass, three coats of WW2 light olive green semi-matte Duracoat. Before repaint/recover, this camera was mechanically excellent but a cosmetic basket case.