Although these are described as regular die trial pieces in the standard references, the off-metal 'trials' of this year were deliberately struck for sale to collectors.
They were struck in the following combinations on both thick and thin planchets.
Copper J1020/P1155 with about a half dozen known including the illustrated example courtesy of American Numismatic Rarities. The Simpson example is slightly impaired.
Aluminum J1021/P1156 with at least 3 known, Simpson's, Queller's and Denali's.
Nickel J1022/P1157 with fewer than half dozen confirmed. These were struck from both proof, AW849, (date high with the 1 in date to the right of the point of the shield, per Ron Guth) and business strike, AW850, (date lower and more to the left with the 1 below the point of the shield) dies as shown below courtesy of PCGS.
It is one of the few die trials known to exist in both formats.
In business strike format, the following 2 are known:
1) Heritage 7/94 ANA lot 7938, Denali - PCGS66
2) Dibello-Stacks 5/70, Crouch-Superior 6/77, Superior 5/90, Simpson-Heritage 9/20, Heritage 11/21 - PCGS62
One of these business strikes is ex Stickney, V. Brand (journal #39032), A. Brand (sold 5/41).
There appear to be at least 3 known in proof format as follows:
1) Denali, Heritage 8/11, Heritage 4/15 - PCGS66
2) Auction 86, Queller-Heritage 1/09 FUN - NGC66
3) Auction 90, Heritage 7/94 ANA lot 7939 - NGC66 appears to be different from #1