Although described in the literature as "regular dies trial pieces", these are actually restrikes (novodels) deliberately made in the early 1870s, from backdated dies, and sold as part of complete off-metal sets of the silver coinage of this year containing quarter, half dollar and dollar which had the reverses of 1866 with the motto "In God We Trust" above the eagle.
The reverse die was used from 1869 to the mid-1870s on die trials with a scratch above the 'NE' in ONE. The obverse die was made from the hub with a broken first "S" in "States". This same hub was also used in 1869 to produce the die used on J718-J720/P799-P802.
Examples were struck as follows:
Copper J381/P449 with about a dozen known.
Aluminum J382/P450 with 2 or 3 known.
Nickel J383/P451 with only 2 believed to exist.
Photo courtesy of Heritage from the G.H. Wolfe collection.