Newbie looking for help with sheffield hallmarked teapot?

Hi, i was left a tea pot by my great grandmother who told me it was silver but i am trying to date it. I have no idea how to make heads or tails of it’s hallmarks and really would like to know some more about it. I would appreciate any info or help i can get :slight_smile:
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Unfortunately I have to tell you that this is not a silver mark. Your teapot is electroplated and was made by E H Parkin & Co of Sheffield some time in the mid-20th century.