I have a Japy Freres Crystal Oval Regulator Clock that my great aunt bought at Butterfields Auction house in San Francisco years ago. It has a mercury pendulum, round bevelled glass doors – front and back and is encased in green marble or alabaster. The face says Shreve and Co, San Francisco. It currently does not run but I think if it was cleaned it would and otherwise it is in perfect condition. I am wondering what it would be worth at auction. I have not been able to find one just like it anywhere on the internet. It says Japy Freres on the movement and Made in France and also has the number 1853.