I believe this is a DDO. The four of the date. No matter which way I look at it with my microscope I can't make that bar go away.
It is a raised area to the East of the 4, and inside the four. The vertical bar of the four is considerably thicker and wider than the normal four for that year.
I lost my filter I made that fits in my microscope to cut reflections and glare. I need to make a new one for better pics. I looked on Coneca maybe ddo15 but they don't have a pic.
Try posting your photos on the CONECA forum...maybe Ken Potter will respond...he is now very active on that forum. Larry Nienaber
I am still not sure about the doubling. I took some pics with a macro lens on my cell phone and now I am doubting it. I need to find that light filter.
Paddyman commented about this on another post. It appears to be the same......Die Deterioration Doubling Check it out on this website. http://www.error-ref.com/die-deterioration-doubling-incuse/