Question - have you ever attempted to make the tiny gears themselves out of clay? Reason I'm asking is I'm going to try some Steampunk claying projects myself and I have some paper-embossing molds and rubber stamps - I'm going to see if I could get some little gears and keys made with those.
I've already discovered on my first foray around town how pricey real watch parts are if you go to buy them from places that know about steampunk and that there's a demand.
However, I do plan to check with a clock repair place and see if they have anything they can't use and would otherwise throw away; maybe they'd sell it to me cheap.
But back to making clay parts - I think it could possibly work and they would look fine on clay pieces at least, properly painted and so on. The main challenge I can foresee is getting them molded and out of the mold without breakage. I'll report back my progress!