Back when I was a kid, there was this kit for a weight-driven clock. I specifically remember that the instructions specified a certain penny-weight of nails for the weights. So my dad and I trekked to the hardware store just to buy those nails. And then I had to count them and stuff them into the plastic casing for the weight. Good times. I think this was the late 70's. Surely the Intarwebz has a picture of everything, but I couldn't find a picture of this thing in several minutes of searching. If anyone finds a picture, please comment and I'll add it to the post.
Anyway, a recent post on BoingBoing reminded me of that. Clayton Boyer Clock Designs designs and sells plans for all sorts of wooden mechanical clocks and orreries. The plans are full-size on paper, which means you can stick them to the wood and cut out the pieces. You can use a CNC, a laser cutter, a jigsaw, a scrollsaw, a router, whatever works. But it's not for everyone: apparently the process is very fiddly to get right, and you have to spend a lot of time making sure the parts are true, and debugging the clock afterwards. Still, it would make a great gift for a high-skilled tinkerer.
(Update Feb 21, 2010) This plastic medieval clock kit from Japan is close, and may have evolved over three decades of being passed from company to company. I do sort of remember the pendulum thing on the top.
This kit is the closest to what I remember, but it's a set of instructions for a wooden kit. The conformation is extremely close to what I remember.
The kit (in plastic) was probably a close copy of this clock from Germany. I also remember it never quite worked right :roll: