Here's the mouse as a tin wind-up toy. (And a cat reacting the way my cats usually do. ;-)

It was easier than I thought it would be. I made the mouse a little rounder and cuter, since that's what the wind-up mice I've seen look like.

What would be the best way to make the key posable (so you could turn it)? Maybe I should just make it a separate prop. That way, it could be positioned at the best angle for any render, even on the side, as many mechanical mice are designed.

Tomorrow, I'll give texture maps another try....