That "point", if it is reliant upon Origen, does not extend towards the OT, for that collection was in no way in flux, according to Origen. For him, that was settled enough.
That many others also considered additional post Apostolic works as "divinely inspired" (not to be confused with fully infallible, perhaps) as far as what was by then spoken of by some as "New" Testament, gives strength to the listing of OT "books" Origen documented as being what was at his own time (and place) regarded as being what the Jews themselves, and those original Apostles (who were Jews) regarded as aligning with the idea of "canonical". I have to say it like that, for although the Jews had the concept of "canon", they didn't quite have a word that translates directly enough for it.
Would what Paul considered as 'canon' when Christ hung on the cross, be what teachings, knowledge & prophecy Christ came to fulfill? Or...can "Christians" coming along later, themselves not Jews, somehow know better than Jews what was the holy writ of the Jews? It matters not, that many did not recognize him. That too, was prophesied. But not all failed to see him for who he was, even from time of his confirmation (at 8 days old) at the Temple.
As to the proper contents of the OT, prior to Origen, Melito confirmed Josephus. Melito related he traveled from Sardis (in present-day Turkey) to Jerusalem to find out...since by his time, there was already some circulation of dispute.
But in Caesarea, it is doubtful there was ever any dispute (as to proper OT canon). There wasn't later, in Origen's time.
Basing OT on what was in LXX continually begs the question (oft asked but NEVER ANSWERED), which version of LXX? Besides, as it has been pointed out more than once, the original work of the 70, was only those books of the Law, or as otherwise known, the books of Moses. Some Jews called that "Torah", putting the books of the prophets, and other writings (like Psalms & Proverbs) somewhat aside as not to be held in as high regard, not to be confused with any other which had been directed by God for them to have written upon their hearts.
You do know the citations for that "written upon their hearts" idea? That is much the origin of sola scriptura principle, for it was tradition among the Jews from ancient times.
Aah, but what have we, but those who would set that "tradition" fully aside, even while pointing at their own traditions said to have come from Christ & the Apostles. There is a glaring inconsistency in the RCC, right there...
The problem is this. The earliest LXX complete manuscript that we have is Codex Vaticanus. All the others are fragments and don’t provide a good answer to the question as to ‘what did the Jews at the time regard as canonical?’
What it does provide is that the LXX includes them. So even if one were to argue that they were of lesser value - the fact that Vaticanus does include them is substantial evidence in favor of the hypothesis that even if of lesser value they were still good enough to be considered canon.
The lists of the Church fathers reflects this too.
The argument that the protestant deuterocanon should not be included, is an argument that we find nowhere before the 16th century. Even though Jerome argues that they are of lesser value - in the end they were included. The only reason for the opinion of Luther is that he read the Vulgate and, not knowing the history behind it (generally being ignorant of such things), came to the conclusion that Jerome spoke for the Church at the time.
The problem is this - no one else took up that argument. There are exactly zero codices after Jerome that have Luther’s list. One would expect that if this position were held by substantial numbers of the Church that one would see this position show up. We don’t.
Instead what we do see are the same lists that the Vulgate has always had, the same list put forth many centuries previous.
I just don’t see any solid evidence to favor the protestant position. It would change if we had a complete LXX before the time of Christ - but we don’t have that.
That leaves us with the secondary sources.
I am not following this thread closely, but I think this was dealt with before. http://www.freerepublic.com/focus/religion/3003863/posts?page=260#260
http://www.freerepublic.com/focus/religion/3003863/posts?page=239#239
http://www.freerepublic.com/focus/religion/2891087/posts?page=990#990
“even in the case of the Septuagint, the apocryphal books maintain a rather uncertain existence. The Codex Vaticanus (B) lacks 1 and 2 Maccabees (canonical, according to Rome), but includes 1 Esdras (non-canonical, according to Rome). The Sinaiticus (Aleph) omits Baruch (canonical, according to Rome), but includes 4 Maccabees (non-canonical, according to Rome)... Thus it turns out that even the three earliest MSS or the LXX show considerable uncertainty as to which books constitute the list of the Apocrypha..” (Archer, Gleason L., Jr., “A Survey of Old Testament Introduction”, Moody Press, Chicago, IL, Rev. 1974, p. 75; http://www.provethebible.net/T2-Integ/B-1101.htm)
All three codices [Vaticanus, Sinaiticus and Alexandrinus], according to Kenyon, were produced in Egypt, yet the contemporary Christian lists of the biblical books drawn up in Egypt by Athanasius and (very likely) pseudo-Athanasius are much more critical, excluding all apocryphal books from the canon, and putting them in a separate appendix. (Roger Beckwith, [Anglican priest, Oxford BD and Lambeth DD], The Old Testament Canon of the New Testament Church [Eerdmans 1986], p. 382, 383; http://triablogue.blogspot.com/2008/01/legendary-alexandrian-canon.html)
And if quoting from some of the Septuagint means the whole is sanctioned, then as said, in principle this leads to affirming even more books which are not in the RC canon
Since the Psalms of Solomon, which is not part of any scriptural canon, was found in copies of the Septuagint as is Psalm 151, and 3 and 4 Maccabees (Vaticanus [early 4th century] does not include any of the Maccabean books, while Sinaiticus [early 4th century] includes 1 and 4 Maccabees and Alexandrinus [early 5th century] includes 1, 2, 3, and 4 Maccabees and the Psalms of Solomon), then you are bound to accept them as well. More on problems here: http://www.aomin.org/aoblog/index.php?itemid=3956
Go to go now...