Sevres Porcelain Pin with CHINA Silver Mark Help?

[treasurehappy]

Greetings to all you Silver Enthusiasts! I hope I can get the image to show this fabulous brooch! I was told the Porcelain Sevres mark is from the 20s-WWII, but the Metal frame is marked CHINA No 23 and S.C.? I think this is Chinese Gilt-Silver? But it looks like Brass?
Can anyone enlighten me to the date and material for sure? Do you think it was made at the time of the Porcelain or made for it?
Thank you so much!

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