Hi
It is a Vienna Regulator and was probably made in Germany or Austria and likely made between 1890-1910. It could be a Gustav Becker clock and may have a GB printed on the rear of the clock mechanism.It looks in very good condition. In terms of value I always go to Ebay and track similar clocks worldwide and see what they sell for. My guess would be that it could be worth say $2000-$3000. Hope this helps