This is something that I came up with years ago. My first attempt was done using a mainboard from a 9 pin, dot-matrix printer. I drilled a hole and inserted a clock motor. It really is that easy. I would like to play a little more with this idea, and am planning to build a few of these.
Below is the clock that hangs in my home office. It was made from the motherboard of a Macintosh SE that I found dead on the side of the road. I only removed on IC chip from the centre and drilled the hole dead centre. I left all the RAM in place. Looks sweet.