Hello all, Not sure if the this is one. The upper seref looks like it could be. If it is not one, could it be a RPM, that is making it look like the 1987 D LMC MMS-12. Thank you for the help, Edward M.
On the mintmarks you have to consider die wear direction. On them to the southwest. When split plating happens it is often in the same direction. The clue that it is on split plating, you can see a gray area in the direction.
This one is a RPM, but when I bought it I didn't see the split plating on the SE direction. (If I had noticed it, I would have passed on it) So depending on your coin, the color would be the clue if it is a RPM or just a split plating issue.