Thomas Bradbury and sons silver salver - is it a fake?

I have a silver salver. (Pics are on whats it worth). I can’t make out any Assay mark, so could it be a fake. It is about 14" stands on four “Claw” type feet, about 1 inch high, and has a gadroon border. It is highly polished and has the motto of the family “GRACE” in the middle. The date letter is definately a D. Thanks in advance!

Shirley