Although described as regular dies trial pieces, these were deliberately struck for sales to collectors as part of complete off-metal sets.
Examples were struck as follows:
Copper J1363/P1508 with the following 4 confirmed:
1) Mitchelson-Connecticut State Library
2) Hughes 7/80, ANR 12/03, Heritage 4/17 - PCGS64RB
3) Peters 1/75, Wyoming collection
4) Farouk ?, B/M 9/98 cleaned, probably the piece graded PCGS63BN
Aluminum J1364/P1509 with only 2 confirmed.
Photo courtesy of American Numismatic Rarities.