Looks like the 74D was struck through something more than grease - some sort of foreign object got between the dies.
Makes sense, so then I would assume it is a mint error and therefore worth more than face? Is this something the grading companies would slab?
They are very hard to find in MS since, given the die state, very few were set aside. I mean, in all honesty, they look like they're all worn out (XF-AU) straight off the press!
Found some pictures that I wanted to stick in this thread in case someone is looking. Here is the die marker for the 82P. The base of the '1' on the date is missing.