The regular dies trial piece. Examples were struck as follows:
Copper/Silver J428A/P500 struck on the same rolled planchet stock used on 2 cent pattern J407/P477 and is said to be native Michigan ore. The unique example shows copper on the obverse with silver on the reverse and is ex Auction 83, Auction 86, Queller-Heritage 1/09.
Copper J428/P501 which, incredibly, has not been confirmed to exist and is the only silver denomination piece of this year not known to exist as a copper die trial.
Photo courtesy of Heritage.