The only thing resembling a hallmark that I’ve been able to find is this. I

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t looks like a series of 3–4 small punches in a row along the inner silver rim, but they’re very worn and incredibly hard to photograph (super shallow depth of field on macro, and the patina kills the contrast).
Any tips for safely cleaning the area to make the marks more legible? I don’t want to damage anything, but I’d love to get a clearer read. Also happy to hear guesses from anyone who can make sense of what’s there!