I was using the sheet in the exponet collection;below your row 5
and the exponet stamps which correspond to the number chart on the
right.The accent over the S is a bit heavier on the left than on
the right.So as all the numbers match up; so I assume it is a type 1.
The inking of the overprint on the left looks a bit heavier,so the accent gives
an impression it is sitting on top of the S..
It must be a re-occuring thing because the two examples match up.
((I changed the colours to make it clearer,screen shot)
Your stamp:

exponet stamps;


