I just picked up this clock at the Mid-South Regional yesterday. I was told by the seller that it is called a "Key Hole" German Vienna clock. There is no makers name on it anywhere. It does have two sets of numbers on the back plate, 42/105 (pendulum length?) on the left and 12370 (serial number?) on the right. That's it no other markings. The majority of my collection is American so I know little about the German clocks and have no references on them. So I need some help on a possible date and maker for this one.