Looks like a corroded ragged end clip. The Blakesley Effect shows opposite. Shame it's also corroded.
Thanks, It is a bit light. I would get some Verdi-care and give it a soak to remove the green Verdigris at the edge. It is a good product. IMO.
Thanks. I 'll check that out and if I decide to clean the coin with it, I'll post some pics of the results.