It's a very distinctive mark that is likely to date from the end of the C19th, given that it states “England”. I did wonder if it could be William Osborn, but can’t find a reference for any plate, or a monogram mark like this attributed to his workshops. This is the whole piece:
The same mark appears on the sconce cover for the central capital. The copper base is starting to show on some highlights and on unreturned edges, so this does appear to be genuine Sheffield Plate rather than electro-plate.
Any pointers gratefully received ...