Salvius would be a praenomen of Umbrian origin; the gentilio Novanius, which is supposed to be nominative, would be a semel dictum or hapax since we only know the nome Novanius. C. Hülsen's hypothesis about the derivation of the nomen Novanius from the city of Novana, mentioned and situated in the Picenum by Pliny the Elder, would be a good indication of the Picene origin of the personage, which would supposedly also prove his praenomen Salvius and his nomen Novanius. In the context of the singularities of this inscription, J. Kolendo points out that the epithet propilius is very rare in reference to Mithras and appears only on one other occasion.
Marc Mayer i Olivé (2010) Dos propuestas de nueva lectura de inscripciones del Maceratese
The Macerata Tauroctony shows Mithra slaying the bull with the usual Pyrigian cap and six rays around his head.
[I]nvicto Propitio / Sal(vius) Novanio / [L]ucianus / d(onum) p(osuit)
To the invincible benevolent, Salvius Novanio Lucianus offered this gift