please help me with this , is this sheffield?

Hi, Can anyone help mw with this pls. ? i know its not silver but would like to know if its silverplated or is it a white metal , also written E P N S sheffield D 3 which i know nothing about it , any help would be appreciated , thank u all [/img]

EPNS is electro plated nickel silver, so its plated but that is all i know. hope that helps