Yes, Jean Louis Galliot of Lyon is the maker; the is the last of his three marks, entered around 1818.Jean Louis Galliot
Born: 31 Oct 1782, Villebois, Ain, son of Jean Galliot & Marie Pitat
Married 1st: ca. 1812, to Louise Duverdy (1796-1815)
Married 2nd: 10 Jul 1827, to Rose Francoise Raton (b.1798)
I cannot find any record of his death in Lyon or his home town of Villebois, though the death record of his only son - Jean Baptiste Etienne Galliot (1813-1849) – indicates that Jean Louis was still alive at that time.
As for the antelope head, the short answer is that no one knows. There are other similar marks on Lyon silver of the period, including a rampant lion, a displayed eagle (which appears on some of Galliot’s output), and a lion’s head in a pelleted surround. Chalabi & Jaze-Charvolin offer three hypotheses for these marks: first, that they were some sort of unofficial pre-assay marks analogous to the Parisian Greek woman’s and boar’s heads (see this thread
); second, that they were the personal marks of individual assayers, and third, that they were some sort of retailer’s or consortium marks.
None of these theories are without their difficulties. Unlike the Greek woman’s and boar’s heads, the Lyon marks appear to have been used on both silver standards and on pieces that do not have multiple components – this plate being a perfect example. The assayer mark theory appears to be contradicted by comparing the working dates of makers to that of assayers which show the same mark on works of makers that could not have been assayed by the same assayer. The retailer/consortium mark seems the most plausible to me, but the problem there is that there is no evidence or precedent to support the theory.
Hope this helps!
Ref: Maryannick Chalabi & Marie-Reine Jaze-Charvolin, Poincons des fabricants d'ouvrages d'or et d'argent Lyon 1798-1940
(Paris: Imprimerie Nationale, 1993), p. 181, mark #821 and pp. 42-49.