Identify hallmark on spoon

I do not have a picture but I saw a set of 5 Demitasse type spoons at my father-in-law’s house in Sheffield, England. On the back of the handle are the letters: L&W (picture of an anchor) S. Can anyone identify the maker , year, etc?

Unfortunately a picture is vital for date identification. The anchor probably indicates that the spoons were assayed in Birmingham and the S is the date code. However each letter repeats on a 25 year cycle with different styles of letter and punch shape.

Assuming that it is silverplate, does the L&W represent any known silversmith?

They are probably silver, not silver plate. L&W may be identifiable, but once again it depends on the lettering and punch style. That’s why pictures are indispensable.