Typical Beefeaters Gin Mirror with Very Rare Old Frame and Stamped Marking and Numbers

I'd really just like any information I can on this. I'm not good with technology as it is and I've been searching this for three days now for hours at a time. (HDHD) Just makes it that more difficult not to get lost in my searches. It has something to do with NEW YORK N.Y. but it looks as if they were made as gifts to establishments or companies. This is TOO HEAVY AND SOLID to be simple production advertising. Any information or direction on how to find out information would be greatly appreciated.