Welcome to the forum. This is a shop piece, that C is most likely the inlayer. Showed a couple of artists I know that work this type of shop work and they didn’t know the mark. It does look like the piece could have some age.
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First thing my search popped up was an inlay butterfly brooch on ebay with the same hallmark AND the pictomark/shop mark which you can barely see on your piece…I copied your pic, rotated and enlarged it to see it better.
Link to ebay item- https://www.ebay.com/itm/323752690240
From the ebay pic, we can see the shop mark better and a search on that lead me to this-
This agrees with @Jason posted about it being a shop piece and the “C” being the inlayer.
At least this provides you with additional leads to perhaps locate the actual artist. Good Luck!
Thank you both so much for your help! I am new here and I appreciate everyone’s generosity. Have a great day.
Thank you so much for your help!!!