1942 D Lincoln Cent - DDO Or Machine Doubling

Hello,

A lady in Indiana recently asked me to check out this Lincoln Cent to determine if it is an undiscovered variety or just something naturally occurring.

Initially, the mint mark had verdigris covering it so I used a porcupine quill to remove the majority of it.

After that step I used a Q tip dipped in residue-free acetone to end up with the photos shown here.

Please opine insofar as what is shown here in the date, mint mark, and any other area of interest.

Thanks

mdpmedia