Found this 1954D Roosevelt in the bullion bin. It has what appears to be part of a dropped letter. My bet is that the dropped letter is actually a piece of another copy of the mintmark. See what you think.
OK. I thought that a dropped letter could make an incuse mark on the die and then it would be transfered as raised on subsequent coins. That is why I thought it might be part of a dropped copy of the mintmark. I stand corrected.