English silver button or cufflink

[andy_mnemonic]

Hi, I found this button or cufflink near Cambridgeshire, England a while back and haven't been able to positively ID the maker mark. I can tell it is English but it does not have a city, duty or date mark that I can tell. I've estimated its age at mid-18th to 19th century but the maker mark isn't very legible so I am stuck there. Can anyone help me narrow down a maker or anything more specific?

Thank you!

--Rob

[silvermakersmarks]

It might be IR (script) - John Rich, active 1765 to c1810.

Phil