On page 172 of Gary Michuta’s book, “Why Catholic Bibles Are Bigger,” there is a table of early copies of the Septuagint and the books they contain. I bring it up because I think it shows, perhaps, that the books you are wondering about are not part of the Septuagint after all. Now, I do not have the book in front of me, but I took notes a while back on it, and I have those. Assuming my notations and the book’s information are complete, the information I am about to give you should be correct.
The earliest copy of the Septuagint in the table is the Vaticanus codex from the 4th century. It contains all of the Old Testament – including the Deuterocanon, except the Maccabees. It does not contain the books you mention.
The next earliest is the 4th century Sinaiticus codex, which is missing Exodus, Leviticus, Deuteronomy, Joshua, Ruth, Baruch, Ezekiel, and Daniel, but includes the rest. It does not contain the books you mention.
The next earliest is the fifth century Alexandrinus codex, which lacks 1 and 2 Samuel, 1 and 2 Kings, and 1 and 2 Chronicles, but contains all the Deuterocanon. It also includes 1 Esdras and 3-4 Maccabees, but not 2 Esdras or the Prayer of Manasseh.
The next earliest is the fifth century Ephraemi Rescriptus, which has only Proverbs, Ecclesiastes, Canticles, Job, Wisdom, and Sirach. It does not contain the books you mention.
Finally, there is the eighth century Codex Basilano-Vaticanus-Venetus, which lacks only Genesis, Exodus, Psalms, and the last chapter of Baruch. It also adds 3 and 4 Maccabees, but not the Prayer of Manasseh of the two Esdras books.
All of these Codices contain Books from the Deuterocanon placed among the other Books of Scripture, but the majority of them do not appear to include 3-4 Maccabees, the Prayer of Manasseh, or the two Esdras books. (It is my understanding that Ezra and Nehemiah are sometimes called 1 and 2 Esdras in older literature. The original Douay-Rheims bible does this, for example. But I think there are also two
other books of 1 and 2 Esdras, apocryphal ones, and those are the ones I am talking about in this post.)
I hope that is helpful. Perhaps you could get Gary Michuta’s book for more information. It’s available here:
amazon.com/Why-Catholic-Bibles-Are-Bigger-ebook/dp/B00E99AU1C/ref=sr_1_1?ie=UTF8&qid=1410020908&sr=8-1&keywords=michuta+bibles
**EDIT :: We can summarize the table this way (assuming I wrote down my notes correctly and Michuta’s table was complete):
There are 5 copies of the Septuagint in Michuta’s table on page 172 of his book.
5 of them contain Wisdom;
5 of them contain Sirach;
4 of them contain Judith; the one that lacks it lacks most of the Old Testament;
4 of them contain Tobit; the one that lacks it lacks most of the Old Testament;
3 of them contain Baruch; those that lack it lack much or most of the Old Testament;
3 of them contain 1 Maccabees; one of those that lacks it lacks most of the Old Testament;
2 of them contain 2 Maccabees; two of those that lack it lack much or most of the Old Testament.
2 of them contain 3 Maccabees;
2 of them contain 4 Maccabees;
1 of them contains 1 Esdras;
0 of them contain the Prayer of Manasseh.
Therefore, I don’t think it’s necessarily true that these four books were part of the Septuagint. I hope that helps. Please let me know.