Ok. the "375" is an EU (modern ) common control mark for 9 carat gold, this number is preceded by a set of scales which also bears the 375 mark. (in the center of the scales)
The UK control mark is a crown followed by 18 (if 18 carat gold) or crown followed by 22 for 22 carat gold until 1974.
So i'm wondering if this is in fact a US mark, that looks like a british hallmark. It's hard to say without seeing the mark.
You might like to try searching in the link "US Jewelry Marks 1922 - From the Jeweler's Index 1922 edition" in the Jewelry Resources. You might find it there.
If you would like us to research further you will need to send in an image of the mark.
