Hmmm. I am not sure.
Double-strikes / multiple-strikes sometimes do really funny things.
On the
reverse I see what looks like the top of a 2nd
standard between the normal
standard and the
head of the figure on the right. But if that is what it is then it is a different
standard design from the main one. When you look at other GR 1-standard coins from
Constantinople you will see that this 2nd design - with a dot at the top point is at least as common as your main design where the dot does not sit on top. This would imply a double strike but from different
Constantinople dies.
On the other hand that
bit might be something else indeed not related to the top of a
standard. Or it might be a
bit of the regular
standard top and the helmet top mixed up. There is a
bit of an optical illusion at play as my eye keeps adding to that to make more of a
standard by "borrowing" the front of the guy on the right's
face. But if you eliminate that then there is not enough to be certain that the bent line and dot are indeed
part of a
standard.
None of the other things you
circle on the back worry me - the helmet of the guy on the right, the dot on top of the spear on the guy on the left. The shields that look like knobbly canes are perfect for
Constantinople.
As for the
obverse. That could be an extra IS at the end. But it could also be the right hand upright of an N plus an S. I think this is the easiest explanation as an NS appears in two places on the
obverse legend already so it would just mean a rotation during a double strike.
It may seem odd to suggest that only the right upright of an N survives but that is the thing with double strikes. They almost always yield these incomplete bits. Your theory of CONSTANTIS calls for a similar cut-off with the IS existing but not the T, so 1/2 the N plus the S is just a matter of a letter being cut-off in the middle.
To me Occam's razor argues for the simpler explanation - a double strike with rotation.
Shawn