Masons Antiques has dated this piece to the 19th Century.
It is highly unusual to find these covers as they have invariably been broken over the years.

The sevres panels are signed by the artist.
The beautiful 8 day clock strikes on a bell on the hour and half-hour. It has a silk suspension. The movement has just been fully serviced by a registered member of The British Horological Institute.
Hunziker is recorded in Loomes "Clockmakers of The World" as working in Paris (Rue de Bussy) between 1800 and 1830
Masons Antiques has dated this piece to the 19th Century.
You can view the stock and full dealer information on the Masons Antiques Profile Page