Although described as regular dies trial pieces, these were more likely deliberately struck for sale to collectors as part of complete off-metal sets.
Examples were struck as follows:
Copper J1264/P1406 with fewer than a half dozen known. One of these is known on a small, thin planchet. This is a mint error, struck on a cent planchet, and should not be confused with the die trial. For additional information about this, click here.
Aluminum J1265/P1407 with fewer than a half dozen known.
Photo courtesy of Bowers and Merena.