Going through an old wheat book today, I found this one. It really looks like a 1952 D over S. What are your thoughts? Below are from PCGS - the first is their Photograde of the 1952 D/S. The second shows where the standard S would be on a 1952.
Certainly no expert here, but it appears to me it might be D/S, but as mentioned, there is too much crud to be sure. It might also be just damage. It does not look like the D/S from PCGS, but that doesn't mean it isn't one.
After a quick acetone bath... I still see the top curve where the S would be - but again the question is - damage or actual D/S?
I'll point out that what you perceive as the upper loop of S seems to continue past the corner of D and proceeds southwest across the field.
Check the various sites for a D/D. MM position is not correct, it's close but not in the same position. MM were hand punched into each working die, the position changes with every die pairing.
Sal's photo is the one I was looking at and wasn't able to upload. While the 52 D over S is slight looking that tail piece underneath the D is important and I am not seeing it on the OP coin.