Hi ~ welcome to the forums.
Unless you find pieces in the same pattern with a manufacturer's trademark, or can find it in a reference, determining the maker is unlikely. By style, it would date from the late 19th century into the first couple of decades of the 20th - most likely toward the end of that window, when 'Sheffield Plate' was a common marketing term for some American silverplate manufacturers. While some pieces were silverplate on copper and were 'Reproductions' of Old Sheffield Plate, they were not fused plate, and this piece, which appears to worn silverplate on Britannia metal, has little to do with Sheffield Plate at all, despite the stamp. The clip below, showing a set of similar form and decoration, is from a 1901 retailer's catalog:


~Cheryl