I think this is Constantine II. There is what appears to be a chi rho on the banner. If so, I believe this makes it a Constantine II. Looking at all the possible mintmarks from Siscia, it could be an A, B, Epsilon, Gamma preceeding SIS and it would seam that it should be a crescent following. But in any case, it would be RIC VII 85 for any one of them. All are listed as common.
BTW, good job cleaning this coin.
BTW, good job cleaning this coin.





















