Although listed as a die trial, struck in silver, in the reference books for years, this is actually a mint error struck on a dime planchet from business strike dies.
The following 3 pieces are confirmed from 2 different obverse dies:
1) Bluestone 9/42, NN61st 6/70, Bass-HWBRF, B/M 5/99, Heritage 4/02 - PCGS63, illustrated above. This has the first one in date roughly centered between Liberty's neck and the dentils.
2) Leidman 9/71, Bass-HWBRF, this and the next have the first one in date closer to Liberty's neck.
3) Woodside, Woodin, Newcomer, Farouk, RARCOA's Boosel and 73 FUN sales, LegendAuctions 1/28/18 - PCGS61, lacquered
One of the last 2 is from Federal Coin Exchange's 8/57 ANA (blue steel toned) and/or Bolt-Stacks 4/66 (toned).
Photo courtesy of Heritage.