Actually all you have done is assert what you believe.
There is no textual evidence for a BC Septuagint.
Nor did Jerome ever view the Apocrypha books as equal to scripture.
Until Trent, many other Catholic scholars felt the same way.
Those are simple facts.
There is no textual evidence for a BC Septuagint.
Ditto. There is plenty of evidence that the separate books of the Septuagint were written well before the birth of Christ. As to when they were compiled into one "codex", who can say? Most articles that I have read date this compilation to 80-100 BC. The Old Testament suffers from this same "problem", as the Hagiographa of the Hebrew canon was not set until well into the Christian era. Thus, your proposition means very little. The fact of the matter is that the individual books (such as a Greek Isaiah) were available and were quoted from or alluded to by the New Testament, more often than the Hebrew version. Considering the New Testament was written entirely in Greek, do you find it surprising that men would use Greek OT sources?
Nor did Jerome ever view the Apocrypha books as equal to scripture
Jerome doesn't call the 7 books that we call "Deuterocanonical" as "Apocrypha", so that is another false premise. Of course Jerome doesn't equate the Apocrypha to Scripture. He calls them "Ecclesiastical" books as opposed to the Protocanonical books of the Old Testament, books to be read in Church to the people, just like any other Scriptural book. When the people at Mass hear the readings, they realize they are the Word of God, whether you call them Apocrypha or Deuterocanonical, or Ecclesiastical books. The typical person heard them as part of God's Scripture. That was good enough for the Catholic Bishops of Hippo, Carthage and Rome in the late 300's to call the Deuterocanonicals SCRIPTURE, since the faithful already considered them inspired and from God.
Until Trent, many other Catholic scholars felt the same way.
Many? Another assertion...