These are also restrikes made for sale to collectors similar to the gold issue J137/P164. For more information on the gold issue, click here. Several of these are known to have been struck over seated liberty dimes, at least one of which is dated 1860.
Additional examples were struck in copper J139/P166, copper-nickel J140/P167 and nickel J140A/P168. These last two should be tested for differences in composition.