In 1943 the U.S. Mint struck Steel Lincoln Cents at Philadelphia, Denver and San Francisco. Most coins came in exceptional quality with many of them being hoarded from circulation since they appeared different than copper cents.
The 1943-D Lincoln Cent is still abundant in circulated grades and even low Uncirculated grades. In MS65 - MS67 condition they usually sell as singles, with most higher graded examples already being certified. In MS67 they are traded frequently and even in MS68. In MS68 condition they are very scarce and highly desired. There are possibly less than 200 examples that exist in MS68 with none being known in any higher condition.