The regular dies trial piece. Examples were struck as follows: Copper J688 This is unlisted in Pollock. If any do exist, they are probably masquerading as a regular issue proof. Copper-Nickel J669/P745 with about a half dozen known. Nickel J670/P746 with only 3 or 4 believed to exist. Aluminum J671/P747 with fewer than half a dozen examples are believed to exist. These were deliberately struck for sale to collectors as part of complete off-metal sets. Photo courtesy of Heritage.