Nice coincidence. We saw the same markings just yesterday!
It’s electroplate from Elkington & Co., early Victorian (before 1866). Can’t quite make out the date letter…
ETA: If you can make out that final punch, you might do some exploration of the images on this page, which would pin down the date more accurately. If forced to guess, I’d say it’s an A, for 1865, but that’s just a wild stab.