This is a hub trial of an eagle, in copper, believed produced by Anthony C. Paquet for use on a double eagle. It is believed to have been made circa 1857 along with his JA1857-9/P3155 and others he was working on.
For additional information on this, please refer to the article on the 1861 Paquet dollars in the ANA Centennial Anthology.
2 appear to be known as follows:
1) ex Schulman, R.B. White, Bowers and Merena 9/89
2) Stacks-Bowers 8/11 ANA, Heritage 1/16 FUN, LegendAuctions 1/18 - PCGS62BN, illustrated above.
Photo courtesy of Stacks-Bowers.