My First Cuckoo Clock

I received this clock for Christmas this year. My fiance purchased this from a man who fixes clocks where we live. And the man purchased this clock from E-bay. I have been searching online everywhere to see how I can tell the age of my clock. It cuckoos and dings, and also plays music on the hour and half hour.

On the back, it is stamped:
DBG. GM. HR. 1727-188
DBG. GM. HR 1770-195
Underneath those stamps, another stamp is: gen gesch= protected by law, patented, copyrighted .
Also there is two dates on the back, hand written:
CFK 9-67
CFK 7-72
It also has what I have assumed to be a price for 168 above the whole where it is put in the wall.
If anybody could tell me anything I would greatly appreciate it!