Britain 1953 enameled Five Shillings, but need more info

I have had this item for a few years, and now looking for more information on who did the rather nice colored enamel with silver struck on the side on the bezel.

Here is the pics:

The bezel is silver but the coin is cupro nickel 

I do know the coin is copper nickel and weighs 28.28g according to the numista page N#5749, and the bezel and lacquer have it weigh 35.3g.

Bump