Ring 18th Century?

by Donna
(England)

Hello, many years ago i found a tiny gold ring with 2 rubies and diamond? We think the hallmark reads CW 12 *5 looks like an anchor on its side with a possible K or H in script. We have looked on the Assay office website and think it to be birmingham circa 18th century. But wanted to know what the 12 and *5 may mean.

Thanking you in advance.

Kind regards Donna and Julie