This pattern, struck in copper, was made using the regular obverse die combined with the reverse with "Cents" in a straight line which was used on J566-J567/P627-P628.
Fuld believed that this was struck outside the mint from dies originally in the hands of Joseph J. Mickley but this is dubious since an example was in Mint director Linderman's personal collection and this reverse was not used with any of the other obverses generally attributed as belonging to these strikings. For more on this, click here.
This was missing in the earlier reference works with the exception of the Taxay book which is surprising as there were several listings for this pattern in the late 1800s and early 1900s.
These listings include the following A.S. Jenks (Cogan 4/1877), Linderman (Scott Stamp and Coin 1888), Woodside (New York Coin & Stamp 1892) and Elder's Gschwend sale in 1908. It is this last listing which I believe led to the AW643 listing which is actually this coin.
At least 3 are known, 2 of which are shown here. The image above is from Heritage January 2006 FUN sale - click on the thumbnail to see an enlargement. The image below is ex ANR 1/06, Heritage 1/12 FUN sale.
The third is the NGC63BN example in the Wilcox collection which has a large spot on the obverse between the 2nd and 3rd set of vertical shield lines.
Photos courtesy of Heritage and American Numismatic Rarities.