It looks like WHAT? Actually, the picture you supplied looks like nothing so much as a dustbin lid visited by several cats and a huge drunk man during the night...  (Oh wait, the reverse is a lot clearer) The Richard Ingrams coin shows a George III guinea, so yours is either a silver copy or a token or a model. It would need very careful cleaning by someone with expertise in restoring coins - have you thought about consulting your local museum?  MDing isn't allowed in Ireland so i'm not sure what to do with it