Very early Christofle mustard pot with Baccarat glass
This quality was befor the process of electrolytic gilding and silver plating.There are also no brands mentioned this was only after 1846.
The attachment on the bottom is also a good indicationWikipedia wrote:It was in 1842 that he began to exploit for France the patents of the Englishmen Henry and Georges-Richard Elkington4 concerning a process of electrolytic gilding and silvering. Faced with the success of the process, he founded in 1845 the company "Charles Christofle & Cie" and began manufacturing as early as 1846 the pieces to be silvered, thus becoming independent of the other goldsmiths.
Also pay special attention to the Baccarat glass with stem, this indicates an old manufacture.
For more info google images "christofle moutardier baccarat