MD, mechanical doubling. It’s flat and shelflike with reduction of devices and it’s also on the mint mark. Mint marks were hand punched until 1989.
What's up Mr. P.? I thought you were tired of offering advice only to be told you didn't know what you were talking about. ~ Chris
What I can also share is that you have a Misaligned Die Strike which caused a slight Finned Rim in this area. Nothing really major but better than Mechanical doubling.
Because you don't want to miss being there the day the miracle happens and someone actually finds one.