Help determine if platter is sterling

Bought this platter thinking it was sterling because of lion passant. It is nearly 6 pounds though and the marking is engraved not stamped. Also the date seems to be altered. Trying to determine if it’s sterling and what the maker is. I thought the b was a date mark but doesn’t match written date

This is almost certainly American electroplate - it is definitely not Brirish. I cannot identify the manufacturer but the marks don’t match those of the Sheffield Silver Company. The word “Sheffield” is often used in the US as a form of shorthand for electroplate.


Thanks for the fast response Phil!