My 2nd day roll searching for errors, so mind my lack of knowledge in the field. This is a 1977-P Lincoln
Mechanical or strike doubling Mechanical or strike doubling - see they way the images seem to be scooted, pushed or pulled? This is a perfect example of die chatter or bounce, ejection doubling all the same thing, not a doublED die. Keep searching!
........the flatness indicates machine/shelf doubling. here is some info on the subject. http://www.geocities.com/NCADD/educational1.html