1955D rpm and something else?

[crocky28]

I found this 1955D sometime during the past month or so and haven't been able to find anything like it online. It's quite apparent that it's an rpm of sorts, but the thing in the first 5 of the date is a bit strange. It almost looks like it could be another mint mark, but I really have no clue. After looking at the pictures on the computer, I also noticed either a notch or some pmd on the 2nd 5. Anyone know what's going on here?

[Pat]

Looks like MDD and not a DDO.. Sorry.. Looking at the 5 looks like it took a hit from something..

[crocky28]

Looks like MDD and not a DDO.. Sorry.. Looking at the 5 looks like it took a hit from something..

that's what I thought...I don't even really see MDD on it. I'm mostly wondering what that thing in the first 5 is, and which rpm it might be (if any).

[coppercoins]

Actually the mintmark is damaged and the 5 of the date exhibits a small amount of surface flaking from lamination. If you took something small and lifted that piece on the 5, it would fleck off the coin.