ADC-1c-1960D-57(SD)
This 1960D small date Lincoln cent shows two clash events. One of the events left a clash mark from the roof of the Memorial building that travels into the 1 digit of the date.
The corresponding clash mark can be found on the reverse die from the right top of the Memorial building roof.
This clash event also has a RPM, identified as 1960D-1MM-109.
The last clash mark, which is through the NE of ONE and into the C of CENT, is a separate clash event. The obverse die was abraded to remove the reciprocal clash mark.
This clash can be recognized by the heavy die scratching on the obverse die and the two diagonal die scratches above the letters RT of LIBERTY.
The reverse die shows three heavy horizontal die scratches just above and through the T of CENT.