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.
Examples were struck in the following metals:
Copper J763/P848 with only 3 or 4 known.
Aluminum J764/P849 as illustrated. About a half dozen are known. These were sold in cased sets similar to the ones in 1868. An example of this was the H.P. Smith set that was purchased by Virgil Brand.
Nickel J765/P850 which is unique and ex Woodin-1914 ANS exhibit, Newcomer, Farouk, Boosel-Rarcoa 4/72, B/R 78 ANA, Superior 1/79, Heritage 5/03.