Help Identifying a Cuff Button Maker

Hello all, I hope you can help. I recently found this silver cuff button whilst mudlarking on the Thames. It is either silver or perhaps silver plated (I think I see some yellow base metal on the reverse?) There is a maker’s mark, BOND, and I think I might see an initial G when I look through my loupe, at eleven o’clock when looking at the BOND mark. Any help at all in tracking down the presumably 18th century smallworker or silversmith would be much appreciated. Thank you!