This is an unfinished reverse die trial, in white metal, of a Heraldic eagle design by Anthony C. Paquet.
It differs from JA1857-7/P3149 in having the eagle in front of a 5 pointed star with rays eminating from the center. Although faint, the motto 'E Pluribus Unum' is on the ribbon.
For additional information on this, please refer to the article on the 1861 Paquet dollars in the ANA Centennial Anthology.
It is unique and is ex Nagy, Kosoff-B/M 11/85, Heritage 1/16 FUN - PCGS63.
A finalized example of this design exists as JA1857-9/P3155.
Photo courtesy of Heritage.