British gold iolite ring

by Joanna
(Colorado, USA)

Hi, here's a question for you...

I have an antique engagement/wedding ring of 18k gold with iolite and diamonds. Try as I might, I couldn't get a good photo of the hallmarks, but the marks are as follows:

Circle within a circle or copyright symbol, 18, 4/10/19 (presumably the wedding date), 712 (where each of these numbers looks as if it were stamped separately), E&W, a crown (inside a square), 18 (inside a square), sideways anchor (inside a square), S (inside a square; I can't tell if it's intended to be upper or lower case, but it is seraphed), and lastly F.M.& B.W. (the initials of the couple).

From what I understand, the anchor means it was assayed in Birmingham, but I haven't been able to dig up anything about the E&W. I'm including a pic of the top of the ring if that helps at all. Thanks very much!