Well Well , I didn't look close enough the first time around but the 1955-S pictured above is a Tilted Die clash. Note the line connecting the URIBUS of PLURIBUS on the reverse. This is a clash from the base of Abes Bust. You should check out the obverse in this area to see if there are any clash remnants there .
Very cool , I always look for these and have found them as early as 1916 .