Hi Ade,
Yes I know what you mean - it is a
bit different - those tokens are worth a
bit so perhaps you should keep up with the detecting.
It could have been nailed to something (a door lintel perhaps) as a charm, and then filled in again later - though it is puzzleing as to why bother.
The
reverse looks semi official, certainly based on a real coin at least, the
obverse looks more amateurish though I can see the similarity with coins of, say Offa etc.
Maybe those helpful people at the BM could provide a clue?
Malcolm