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. On the actual coin, the half eagle side should have a wider border as it is a smaller obverse.
Photos used are courtesy of Heritage and Bowers and Merena.