Judd 187a is a unique die trial of an 1857 Flying Eagkle Cent on a Copper-Nickel planchet. The metal composition of this piece has been reported as 75% Copper and 25% Nickel -- the same alloy used on Three-Cent "Nickels" beginning in 1865 and all regular-issue "Nickel" coins thereafter.
The earliest appearance of this piece was in a 1977 Stack's sale. Ove the years, it has been called both Mint State and Proof, though the current opinion is that it is a Proof. The last appearance of this example was in 2009.