For me, your second-to-last pic is the most telling. I agree that there are two things: one attached to the number 9 which looks a lot like the top of a letter D mm and a curved bit below the number 9 which looks like the back of a letter D mm. However, when taken together, they don't seem to add up to the correct shape. You could overlay the actual mm on this region to confirm that this hypothetical mm would be too skinny and tall. My best guess is that you have a die chip and a bit of a gouge or polishing mark on the die.
"The danger we all now face is distinguishing between what is authentic and what is performed."