The following appears to be an obverse die trial of the 1910 Lincoln cent. It is struck on an oversized irregular copper planchet that is the weight of a standard cent. It is unknown if this is a deliberate die trial or some sort of die cap mint error. It has been graded as AU58 by PCGS as a die trial and not a mint error.
Its status has a die trial, it would be JA1910-1/P3528, has been questioned and thus has not been placed in the new Judd book.
Mike Diamond in an article for Coin World published on July 14, 2014, and titled "Scrutinize claims of experimental planchets, test strikes; they may be error coins instead" noted: Our last example, a 1910 Lincoln cent, is currently encapsulated and labeled as a uniface test strike. It is classified as JA1910-1/P3528 by uspatterns.com, although with some caveats. I think the caveats are warranted and should be elevated to serious doubt. The coin’s weight has never been reported and may be the same as a cent (its color is certainly the same). While the planchet has been described as “slightly larger than normal,” I don’t see any basis for this conclusion. The coin was struck out-of-collar and the portion of the coin lying beyond the die-struck obverse design shows obvious radial striations all around. This would indicate that the planchet was originally no wider than the die face and that the unstruck perimeter squeezed out from beneath the die during the strike.
The available evidence indicates that this is probably a uniface broadstrike. In other words, a cent planchet was struck on top of another cent planchet while neither was confined by the collar."
Photo courtesy of Mike Byers.