This is generically known as “medallion” flatware. Many of the leading makers produced variations on the design, which was highly popular in the 1860s and 1870s. I checked the pattern references and couldn’t find that exact design from any of the major manufacturers, or even any of the smaller ones. Perhaps the closest was Hall, Elton & Co’s 1867 pattern (also produced by Simpson, Hall & Miller):
I suspect it’s from an obscure maker, and perhaps loosely copied from one of the many known patterns.