What this coin looks like (obverse, reverse, mint mark location, special features, etc.): The Denver Mint produced a major Overpunched Mintmark (OMM) error on the 1944 D Lincoln Wheat Cent (Penny). The best way to identify this error is to note the "D" mintmark stamped on top of a subtle "S" mint mark (D/S OMM). The location of the "S" is depicted by the arrow in the example image above where part of the "S" is best seen above the "D".
Coin value chart: Typical coin prices, values and worth in USD based on grade/condition