Trying to determine the age of an antique gold ring - S & W + Crown.

I have a ring that belonged to my mother, she was from england. I believe the ring belonged to her before she married but I'm not sure.

I would like to try and get an idea how old it is. It is a simple band which could be used as a wedding band. It is silver (looks like leafs) then a gold trim.

The markings are S & W, "crown", 18, lions head (in research means london), letter "U". This is on the inside of the silver part of the ring. Something very small on the gold part but it is too tiny to see with a magnifying glass.

Thank you.