The idea of using a cassette tape motor came from this Website from HowlHaunter:http://home.comcast.net/~pumpkin1000/props/13hourbig.htm
He used a lid from a five gallon plastic bucket, painted a 13 on it, and lit it from behind with green Christmas lights. It spun backward and looked OK (see picture), but I wanted mine to look like a real clock.
Next year, I will look for a really gothic clock like the one shown below, and use that for the body. To make things much easier, I will remove the front glass, then attach the motor securely inside the clock body. Then, I can easily adjust the height (projection) of the spinning hand before I epoxy it onto the cassette sprocket.