Did Justin Martyr Read Ancient Platonic Texts in Latin?

An interlocutor of mine once claimed that Justin Martyr possibly wrote in Latin and used Latin translations of Plato. In this regard, some of you might recall that Justin was a Neoplatonist who was born in Flavia Neapolis (Nablus). While I agree that Plato was eventually translated into Latin, do we have evidence that his writings were already rendered into Latin by the first-second century CE? Do we have evidence for pre-Christian Latin MSS of Plato's writings or artifacts that would have been around for Justin to use and is there any indication that he used them?

Jerome (Commentary on the Epistle to the Galatians), who was born in Stridon (located in the Roman province of Dalmatia) and died in 420 CE declares that only "a handful of idle old men" knew either the works or name of Plato in his day. While the scholar's account is undoubtedly rhetorical flourish to some degree, Raymond Klibansky observes: "As far as we know, surprisingly few translations of complete [Platonic] dialogues existed in late antiquity. Cicero's version of the Protagoras was known only to a few erudite men like Sidonius and to learned grammarians like Priscian; that of the Timaeus comprised no more than a small part of the work; Apuleius' translation of the Phaedo seems to have been a rarity, and disappeared, like Cicero's Protagoras, after the sixth century" (The Continuity of the Platonic Tradition, pp. 21-22). So, there is evidence for a few Platonic Latin translations existing in the first-second century BCE/CE, but these works were not that accessible and further research discloses there is only so much information about Plato that a scholar like Justin Martyr could have extracted from these Latin translations anyway. Additionally, he had to know Latin in order to read them. Admittedly, some sources argue that he did.

To illustrate what I mean, consider Gerard Boter's (The Textual Tradition of Plato's Republic. Leiden and New York: Brill, 1989) comments about ancient Latin MSS of Plato's Republic:

(1) The only direct Greek quotations of the Republic in the Platonic Latin MS tradition appear in Cicero's speeches. Verbatim translations of the same work occur in Cicero, Ammianus Marcellinus, Hieronymus, Calcidus, Valerius Maximus and Arnobius (Boter, page 287).

(2) References or allusions from Plato's monumental book (the Republic) are again found in Cicero, Apuleius, Calcidus, Macrobius, Augustine, Boethius, Lactantius, and Tertullian. I think this data should demonstrate that there were not a large number of Platonic Latin translations floating about Rome's territory in Justin's day. One either read it in Greek as did Cicero and no doubt Justin and Tatian or one relied on what those who could read Greek had to say about the Platonic text. It thus seems highly unlikely that Justin was privy to a Latin translation of Plato's Republic or Timaeus. Moreover, when he taught pupils like Tatian, he probably communicated in the Greek tongue to them.