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 only 2 or 3 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 (journal #92500:1177) as the piece appears in the 10/27/36 consignment to B.G. Johnson. Later pedigree includes Goldberg 10/00, Superior 1/04, Simpson-Heritage 1/21 - PCGS65.
Photo courtesy of Ira & Larry Goldberg's Coins & Collectibles.