Thanks! you led me to the relevant AMNG section: Gaebler, Plate XXVII and more interesting notes from Nomos: "Gaebler assigns all the known issues of Eion as being products of an "uncertain" mint. This is actually logical as the type was attributed to the city because of a small H (the first letter of the ethnic Ἠιών) that appears on the obverse of some coins. In fact, other letters, aside from H, also appear on the obverses of the coins of "Eion" - A, N, O, which, effectively excludes the possibility that we have the first letter of an ethnic. The known find spots for coins of the "Eion" type also seemingly disprove the link to the Eretrian colony at the mouth of Strymon river."
Constantius II (337-361AD) AE3 - 2.73 gram - 17 mm, Antioch mint, struck 348-350 AD Obverse: DN CONSTANTIVS P F AVG, pearl diademed, cuirassed and draped bust right Reverse: FEL TEMP REPARATIO, Phoenix, radiate, standing right on globe, star in right field, ANB in exergue Reference: RIC VIII 129 var