I found this today. It looks like a counterstamp, when do you think it would be from. Is there also the chance it could be a coin weight, it seems very thin, maybe two in a halfpenny based on it's thinness.
There is a guy on the PCGS chat forums who was on a hunt to prove a copper he has is one of them. He posted a little bit of info, but apparently no one really knows what one looks like for sure. Here are two threads he posted about them. Suppose as long as yours meets the few broad parameters, you can claim it's a possible one too!
What a shame this really old looking item, isn't so easily recognized. You could always try psychometry to figure it out. I've read that cops have used it in attempts to solve cold case crimes before.