That appears to be the E/EPU…those letters are incused…(incused MD). I think there is a section on it at error-ref.com…Spark
Mechanical doubling. Its not unusual to see this on the incused letters near the rim These dies were made using the single squeeze process, so the mechanism responsible for doubling is different than the classic hub doubling. Class IX Doubling is most often found on the central design elements. For some good info, check out the error-ref link and scroll down to Class IX http://www.error-ref.com/doubled-dies/
