Help With Hallmarks on a 19th Century French Chalice

Im hoping someone can help me. I know the maker’s mark is Jean-Charles Cahier, According to one of the silver hallmark websites, the round cartouche hallmark with the face that ends at the neckline is the middle guarantee for gold. I brought it in to a pawnshop, and first the guy said its 8ct, then he said its plated. There is one other mark but it is nearly completely rubbed off.
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