Found this beauty in a coin roll I picked up in Vt. Can't find a match but looks like a DDO to me. Lou
What you are seeing on your mint mark is what you are seeing on your date, it is all strike doubling. At that magnification level you will see it almost anywhere on almost every coin. The mint mark was not on the master die then, btw. It pays to remember that when you are looking for these insignificant doubled dies.