I came across this today and was wondering if it could be an OMM or RPM. It kinda looks like dmg but at the same time...doesnt,lol. What do you think?
I'm not a Die Variety specialist, but it looks like damage/contact marks (left of bottom of MM, and at bottom of MM) rather than a prepunched mintmark,.
I just scanned through the 91 45P RPMs on varietyvista and didn't see anything resembling your coin. I believe it to be damage.