The closest I can find is RIC 589, with the only difference being RIC 589 has a laureate crown, and this one has a radiate crown. Everything else is the same. Would I just call this a "RIC 589 Var"? Many thanks for any help with this.
I found your coin sold at Marcinak in May of this year. https://aukcje.gndm.pl/en/coins-vespasian-69-79-dupondius/715302 This is their description. Vespasian (69-79), Dupondius Obv. IMP CAES VESP AVG P M TR P COS IIII CENS, radiate head of Vespasian to right. Rev. PAX AVGVST / S C, Pax standing to left, holding an olive branch in her right hand a caduceus in her left. Ae, 26.7-28 mm, 12.84 g Ex Numismata Berlin 2018 Reference: RIC 583 Here is the reference of the type @OCRE: http://numismatics.org/ocre/id/ric.2_1(2).ves.583 It shows one other example held at the Münzkabinett Berlin: https://ikmk.smb.museum/object?id=18228520 Hope that helps.