Hello Phil,
This type was issued by Constans and Constantius II, the reverse is VICTORIAE DD AVGGQ NN.
The obverse legend looks like it fits Constans, which is CONSTAN-S PF AVG
On the reverse, the exergue is hard to read, but the ivy leaf between the victories means it is from either Trier or Rome. The style looks like Trier and I am pretty sure that I can see three letters in the exergue, so either TRP or TRS.