Sounds like a project for you, Jim! If you make it, we can make it a sticky topic.
Interesting, they don't really say much about coating anymore. They used to say "triple nickel-plated steel grates" and now they just say "plated steel grates". And gauge of material seems a bit less than a few years ago.
I guess I'll just have to do that- maybe a trip to the big BBQ store so I can measure the grates. Weber's web site only refers to the nominal size of the kettle, not the grate sizes.