It looks like you have a Gustav Becker Regulator A (or Vienna Regulator) clock. It is probably from the very early 1900's and is a very collectible clock.
Becker is well known for the highest quality German clocks from this time era and are actively sought by collectors.
Thanks for your submission, Bill
Gustav Becker clock by: Anonymous
Hi
Gustav Becker was a German manufacturer of fine clock from the early to late 1900's. The stamp Medaille D'or means that Gusta Becker won a gold medal at a World Fair. As it has a single weight it is a timepiece only - it would be more valuable if it were a double weight with striking mechanism.
If you google Gustav Becker you will find a web-site for Gustav Becker which is quite informative. If the clock mechanism has a serial number then from this web-site you would be able to date this clock.
To check current value I would suggest that you check EBay Worldwide to track a similar clock to see what it sells for. Hope this helps