It is definitely a "Sheffield Plate" coin. I do not recognize the type but I have not tried really hard to do so. I classify it as Class 1 (Contemporary Circulating)
I am snipe bidding for that one but if anyone is super interested in it I would pass. I would advise however, that I know two other specialists who are also watching that one and I do expect the price to go over $100. So if anyone is interested above the $225 level let me know.
It appears to be a poorly attached plate - like many of the Roman fourees were. I expect it is cold rolled over a "white" metal as opposed to copper because of the delamination. It took the Sheffield manufacturer's some time to perfect a Silver on white metal plate that was successful in use. I also believe the obverse could be peeled off just as easily. I see a large loose spot on the King's neck.
For me the most interesting feature would be the edge application more than the face dies. The early white metal copies all peeled on the edge BEFORE the faces - so I expect there is no edge left at all.
Is it possibly a forgery made recently? - Good question.
I do not know. The portrait is TERRIBLE so I guess it could be. It certainly is not up to the standard employed in the Birmingham mints supported by the English government. But I have not seen one of this type yet - they are striking Riddell varieties but so far I am not aware of a decent Sheffield copy of a Portrait. But it would definitely be interesting.