1932/31 United States Assay Commission Medal. Bronze. 51 mm. By John R. Sinnock and Adam Pietz. JK AC-77a. Rarity-7+. MS-69 (NGC). Bright golden-bronze surfaces border on pristine. From the 1989 reference <em>Medals of the United States Assay Commission 1860-1977</em> by R.W. Julian and Ernest E. Keusch:<em>"This mule used, by accident, a 1932 Assay obverse (AC-76b) and the reverse from the 1931 Assay medal. Discovered by John Jay Pittman, for a long time his was the only example known. In 1985 a second specimen...was found by Carl W.A. Carlson."</em>The second example referred to in the Julian-Keusch reference was sold in our (Stacks) sale of the Keusch Collection, November 2008, lot 5329. We are aware of two others: the present example, which is undoubtedly the finest, and an NGC MS-64 sold as lot 3007 in our Winter Baltimore Auction of November 2014. Extraordinary quality and eye appeal, and a significant rarity that is sure to catch the eye of advanced collectors of Assay Commission medals. From the Richard Jewell Collection.