Can you post the other
side of your coin and its size (and
weight)?
It is definitely SMT, indicating Thessaloniki
mint. It should be followed by a S but that edge is a
bit messed up.
I think I see an A in the left
field so it is likely the 5th issue. If that is actually an M it is the 6th issue and there was another letter after the S in the original
mint mark.
SC