Foxed by silver marks. Can anyone help please?

Hello silver enthusiasts. My on line search has drawn a blank in identifying these silver marks, can you offer any suggestions please? The marks are on a pair of fiddle pattern sugar tongs.
Any information you can give me would be much appreciated.
CIMG4155 - Copy - Copy.JPG
CIMG4155 - Copy.JPG

This is an electroplate mark of Thomas Prime & Son of Birmingham. MP stands for Magneto Plate - I’m not sure whether their process differed markedly from standard electroplating.

Thank you for the information, that helps me greatly in cataloguing my silverware. :smiley: