Silver plated napkin holder - Circa 1940

Hi, I have a silver plated napkin holder, oval shaped 45mm (1.75 inches) max diamater. It stands 25mm (1 inch) high. The top and bottom edges are tiny “beaded” and inwards both ends is a design border that looks like a joined series of the number 5. The space between these “5” borders is a fronded leaf pattern running around the napkin with a clear engraving patch on opposite sides of the napkin. One patch has the name “Yvonne” (my late sister) within it and the other patch has an identifying stamped number series from which I cannot identify the maker. These are a separate upper case “A” followed by I think is smaller font upper case “EP” (or maybe just a “P”… the first letter is worn a bit) then “NS”.
Again, I have refrained from attacking it with cleaner/polish lest I damage it.
Can anyone confirm vintage, the maker and its approximate worth?
My pics are too large to be posted… (how can a pic be under 256 KB?)
Gratefully appreciated.
Ron