If you are trying to say that this Latin was from a Sinaiticus text, using the false date for Sinaiticus, there are various problems.The Antehieronymian Latin Version, published by Sabatier, from the Greek
From the French:All of the Hebrewisms of the Codex Sinaiticus can only be explained by translation from the Hebrew. It remains to be seen whether the Hebrew text is the original. If need be, it could itself be the translation of an Aramaic text.
Paul Jouon (1871-1940)L’ensemble des hébralsmes du Codex Sinaiticus ne peut guère s’expliquer que par traduction de l’hébreu. Il resterait à savoir si le texte hébreu est l'original. A la rigueur il pourrait être lui-même la traduction d’un texte araméen.
Author of a philological and exegetical commentary on the Book of Ruth (1924), he also wrote A Grammar of Biblical Hebrew for which he received the Volney Prize from the Institute of France. First published in 1923, Joüon's grammar, enjoying numerous editions as well as an English translation, continues to serve as an important reference to this day.
Finally, certain textual differences between the Sinaiticus and the Vetus Latina indicate that the Sinaiticus text is not necessarily equivalent to the 'original' long Greek version.40
40 Cf. WEEKS, Some Neglected Texts of Tobit, 23-24.
Since, at the very least, it seems probable that the Reginensis version derives from a Long Greek version rather different from both Sinaiticus and ms. 319, this would seem to indicate that either the Oxyrhynchus or the Reginensis text must reflect the existence of yet another Greek text-type within the Long tradition.
"Consequently, one has to begin the study of the Latin Long Recension of Tobit with that given by Brooke-McLean-Thackeray,19 which reproduces a form of the Latin text of P. Sabatier." p.7 Fitzmyer, "Tobit".
But, while the editors are not prepared to express a definite opinion on the old problem of the relation of the two Greek texts of Tobit, they seem inclined to repudiate Swete’s opinion that the Sinaitic text is secondary. They explain the closeness of the Old Latin MS C to the Greek of Sinaiticus as due to the correction of C from an older form of the text into agreement with Sinaiticus. It may be worth noting that Hermann von Soden and H. J. Vogels have argued that Sinaiticus in other areas has been corrected to an Old Latin text.
The problem with the long Greek recension manuscripts that were a source for the Vetus Latina is that they don’t exist. Such theoretical manuscripts do not have a lot of pizazz!Your problem is to account for the existence of the Vetus Latina independently of a Long Greek recension: as to which, the existence of Sinaiticus is irrelevant.