Although listed as a regular die trial piece, these were more likely deliberately struck for sale to collectors as part of complete aluminum sets.
Only 2 examples are believed to exist as follows:
1) Farouk, Kosoff 66 ANA, B/M 10/87, Superior 10/89, LegendAuctions 12/22 - PCGS65, illustrated above, click on the thumbnail to enlarge.
2) Bolt-Stacks 4/66?, Stacks 76 ANA
Photo courtesy of Legend Auctions.