Hallmark help on spoon please

I can’t identify the hallmarks or maker’s on this spoon.
It’s a King’s pattern egg or mustard spoon. Long handled with a silver gilt bowl. Not particularly old or valuable.

Marks are a bit worn but immediately identifiable as an electroplate mark of Elkington, Mason & Co of Birmingham. Unusually for electroplaters EM&Co used a private date coding system and the M in the diamond is their code for 1851. See Elkington electroplate and silver plate: marks, hallmarks and date letters.

Phil

Thank you very much Phil.