I read these marks as being from Paris, 1809-1819, not 1817-1819. You have the silver standard mark of a walking cock facing right, the guarantee mark for medium-sized objects of a Minerva head facing right in a circular reserve, and as a bonus you have a recount mark of a fleur-de-lys from 1819.
Don’t know what your “usual places” are, but Arminjon lists the maker as Antoine-Jean Mahon, symbol a horse head in profile and an acorn. Mahon registered in 1819; his mark was erased in 1834. Thus you can date your beaker quite well. Mahon worked at several locations. During the time he made your beaker, he was at 14 rue Simon-le-Franc. Mahon made small silver objects: cigar cases, rattles, thimbles, keys, etc.
Hope this helps.
See Arminjon, v. I, no. 00310, p. 71.