The vase, in my view, is close to Agora XXIII, no. 1475 (possibly by Lydos), 560-550 BCE. It also has a plain black glossed rim and a thin red line below it. The head of the man is similar as well.

Two letters are preserved, which might be the beginning of a personal name, however, most names that begin with this combination of letters are Thracian and attested in the Hellenistic and Roman periods, except, of course, king Ῥῆσος of Thrace, an ally of the Trojans in the Iliad (10.435). LGPN online V4-12116 lists a certain Ῥηβούλας from Odrysai, Thrace in 330 B.C.E. (Tod, Greek Historical Inscriptions II 193, 1, = FRA 2574).

Place names such as Ῥήγιον and Ῥηνεία also come to mind, and we know of many dedications, especially at international sites such as Naukratis or Gravisca, where visitors from the Aegean cities left dedications identifying themselves by both their given names and their ethnics. In our graffito, if a personal name came before, i.e. to the left of, the painted image, and the inscription continued to the right of the image, we would perhaps expect a definite article introducing an ethnic.