This is now believed to be the first design made by A.A. Weinman per the research of Roger Burdette. This used to be J1798 in earlier editions of Judd.
Fewer than a half dozen are known including the illustrated piece ex Bowers and Merena's Pryor sale. Another is in the Smithsonian. To view that piece, click here.
For pedigree information on this and other 1916 half dollars, click here.
Photo courtesy of Bowers and Merena.