Good scores.
I can’t find that same mark, but I think this is not a piece from Sheffield in England, and may not even have been made by the “Sheffield plate” process. I would be pretty sure it’s American and that the N/S is for “Nickel Silver” (ie base metal) which may well be silver-plated but it’s almost always electroplated.
Especially during the late 1800s and first half of the 1900s, many companies sprang up in America using words such as “silver, Sterling, Sheffield etc” in their company name (or as trademarks) together with fancy looking marks and pseudo-hallmarks mimicking those seen on English items… all intended to evoke a higher quality image for what were usually electroplated wares.
One such company was the “Sheffield Silver Company” founded in Brooklyn, NY in 1908. They mostly made silverplated holloware (such as coffee and tea sets, trays, platters and tableware) together with a small amount of Sterling silver. History and documented marks are a bit thin on the ground but I think this has a connection to that company. By 1917 it was being managed by Morris Fred Hirsch (preferring to use his middle name of Fred) at W34th Street NY. It seems that by around 1920 he had his own company in Jersey City NJ as the “M. Fred Hirsch Company” using both “FMH” marks and “MFH Co” marks at different times. Around 1945 he was bought out by Fisher Silversmiths and then acquired by Reed & Barton in 1974.
I can’t confirm it by showing you a matching mark, and it may not even be documented, but I strongly suspect this is from Hirsch’s company and is electroplated nickel silver. His sterling items were marked as such.
