This is believed to be a striking from two Paquet reverses, one of which appears to have been ground down. Early editions of Judd book incorrectly list this as a die trial.
Analysis of the Queller coin by Dennis Terrant and Heritage has proven that the ground down reverse was, in fact, the Broken Ribbon variety as shown by the comparison images below courtesy of Dennis Tarrant and Brandon Gabrick.
At least 2 examples are known. The Pollock pedigrees are incorrect.
1) Metzger (H. Chapman 2/1909 lot 118) to Brand (journal #47955), Farouk, Bolender, Hydeman-Kosoff 3/61, Bowers and Merena 9/88, Queller-Heritage 1/09 as NGC63BN, Simpson-Heritage 11/20, Atherton-Heritage 5/23 - PCGS63BN, illustrated above courtesy of Heritage. The Metzger description specifically mentions that for the reverse "Parts of same device just show".
2) Lohr, Cox-Stacks 4/62. This is now in the Smithsonian and is different from the first in that this coin is fully uniface, with reeded edge, showing only the reverse as illustrated below courtesy of the National Numismatic Collection of the Smithsonian Institution.
This piece is possibly a mint error in which 2 planchets were fed into the dies at the same time. It weighs 189.1 grains and does not appear to be an example which has had its obverse planed off.
Earlier listings for these include Cogan 9/1869, Fewsmith (Mason & Co 1870), Lefferts (S.H. & H Chapman 1881), Woodin-1914 ANS-Newcomer and Elder's 4/27/17 sale lot 401 apparently to Newcomer. All 5 listings are described as reverse blank like #2 above. The Newcomer inventory shows 2, one of which is heavier than the other. From this last listing, it appears a third specimen exists somewhere in the numismatic ether.