This strange concoction was made by Montroville Dickeson combining the rusted half eagle obverse used by him or Joseph Mickley to strike J38-J40/P6110-P6120 combined with the eagle on shield obverse used on JC1792-3-JC1792-4/P6015-P6020.
Examples were struck in copper with probably 3 or fewer known. It may in fact be unique! Old listings for these include Haseltine 4/1882, Frossard's 5/1882 and 9/1890 sales and the Brand journal lists one under #68340. The last modern listing noted is lot 596 in Kosoff's 5/55 sale.
Photos are a composite in the wrong color and are courtesy of Heritage and Bowers and Merena. As the reverse die is larger in diameter, on the actual coin, the half eagle side should have a wider border unless the planchet was trimmed after striking. This will not be known until the actual coin reappears in the marketplace.