Here are a couple of quotes you might find interesting, related to the subject.
"The Syriac translation of Book VI of the Jewish War, which is
preserved in one of the codices of the Peshitta Old testament, dating
to the 5-6th centuries and at present in the Ambrosian Library in
Milan... H. Kottek thought it possible to show that the Syriac
translation, which differs to a significant extent from the generally
accepted Greek text, may go back to the original Aramaic version
written by Josephus." (Josephus' Jewish War and its Slavonic Version:
A Synoptic Comparison, by Henry Leeming, 2003, Brill; ISBN 9004114386)
"Josephus first wrote the history in his native Aramaic and circulated
it in the East, and then translated it into Greek for use in the Roman
Empire. Thus there is nothing at all improbable in the supposition
that Syriac-speaking Christians knew the de Bello Judaico of Josephus
in its original Aramaic form." (The Syro-Latin Text of the Gospels, by
Frederic Henry Chase, 1895).
Push b'shlama,
Ya'aqub Younan-Levine
http://pshitta.org/