Although these are described as regular die trial pieces in the standard references, it is more likely they were deliberately struck for sale to collectors as part of complete off-metal sets.
Examples were struck as follows:
Copper J1446/P1591 with only 4 or 5 known, at least 2 are gilted.
Aluminum J1447/P1592 with only 2 or 3 known, including the illustrated example and another that has been gilt.
Note: The die trials of this year are often found gilt due to the extreme rarity of many of the gold denominations.
Photo courtesy of Tangible Asset Galleries.