1940’s Hallmarked Silver-Plate Expandable Trivet/Hot Plate In Great Condition

Description

A 1940’s Silver-Plate Expandable Trivet/Hot Plate.
It was a wedding gift in 1944.
There is a Hallmark (a “Castle” a “W” and a Crown”) that is photographed.
I could not determine who it is?
A better mid-century silver plate Trivet/Serving piece in very good condition,
Thank you.