Unknown Calender Clock

Went to an antique store today and saw a Calendar Clock that was in pretty nice shape on the outside. Wanted to see the works but couldnt get into them from back and didn't see any way to get into without moving arms.

Would like to know make if possible and what it is worth. It is all wood about 14 inches tall. where the pedulum is is about 3 inches tall with a glass window so you can see pendulum move. There are three arms. Two for time and one for date. One key hole and the only markings are a small fancy S under the key hole. Any ideas. Thanks Sam