Although described as a regular dies trial piece, these were actually deliberately struck for sale to collectors as part of complete off-metal sets.
Examples were struck as follows:
Copper J680/P759 with about a half dozen known.
Nickel J681/P760 with only a one or 2 known. One is ex Brenner-1914 ANS exhibit, Brand. This or another is ex Edgar Adams-Elder 4/35.
Aluminum J682/P761 with about a half dozen known.
Photo courtesy of Heritage.