gilbert clock face says gilbert 1807

I bought a building when a lady died. She had lived in part and ran a bar from the front and back. I do not know how old she was but I have had the clock for 25 years myself. She was a Senior in 1920 because I have her year book, class ring and a hat and dress. I do not know anything about the clock. If any one could give me some information I would appreciate it. How much is it worth and when was it sold.