1787 New Jersey Copper M73-aa W5430 R4 Plaited Mane VG-Fine Struck Over

1787 New Jersey copper, M73-aa, W5430, Plaited Mane, R4.  This example grades VG-Fine and as usual for the variety, it's dark and struck over another coin: but WHICH coin?  There should be enough undertype, especially on the reverse, to determine what the host coin was here, but that's not something that I care to undertake.  How about you?  A RARE variety, and maybe the undertype will be rare too?  Purchased from Leonard Massa on 10/11/22.