These regular dies trial pieces were actually deliberately struck for sale to collectors in sets.
These were struck in the following combinations:
Copper J1071/P1207 with about a half dozen known including the illustrated example above. Click on the image to see an enlargement.
Photo courtesy of American Numismatic Rarities.
Aluminum J1072/P1208 with fewer than a half dozen known.
Nickel J1073/P1209 Illustrated below. This coin is believed to be unique and was originally part of Judson Brenner's collection shown at the 1914 ANS exhibition to Virgil Brand as the piece appears in the 10/27/36 consignment to B.G. Johnson. It recently appeared in Goldberg 10/00 and Superior 1/04 sales.
Photo courtesy of Ira & Larry Goldberg's Coins & Collectibles.