Please confirm my ID. I have this one as Volusian / likely Concordia or Pax. There is a paterna over the S that you can see in hand.
From what I see and what acsearch easily depicts, i'd say you're right and the reverse is probably PAX..... but still could be Concordia (any legend visible on the reverse in hand?)....and probably RIC 256??? http://www.acsearch.info/search.html?term=Volusian sestertius&category=1-2&en=1&de=1&fr=1&it=1&es=1&ot=1&images=1¤cy=usd&thesaurus=1&order=0&company=