Hi, I can't tell from the images but to clarify: An OMM is an Over mint mark and is used to indicate something involving different mint marks like a D over S or S over D. What you have may be an RPM which stands for repunched mint mark and that involves duplication of the same mint mark , like D over D or S over S. I still can't tell if your coin is an RPM from these pictures though. Thanks, Bill
Thanks Bill, I can't tell either, even under a microscope. Looks like it might have parts of a secondary D mint mark north of the primary one.