Confused by Sheffield marks

My mother gave me a veined meat platter with markings that suggest a different date than the date stamped on it. And in my research I haven’t found anything about marking “Sheffield” and the date under the traditional marks. Can anyone offer any insight into what I have? Thank you very much!
silver platter marks.jpg

This is an electroplate mark of the Sheffield Silver Co of Brooklyn, NY. The number is a pattern number and not a date.

Thank you sir! I was apparently rummaging through the wrong continent. Brooklyn makes lots more sense, though not a particularly interesting story.
Thanks again.