Slimboyfat,
Actually, I've worked on an interconfessional translation of the Scriptures in the early 2000s between Jews, Catholics, and Protestants. I did some work on the Deuterocanonicals, and with help from members of the CBA I got access to the textual materials that went into the current Catholic NABRE. It used a "patchwork" approach to produce its current 2011 revision of these books, including Hebrew manuscripts previously unavailable to produce English versions of Tobit and Ben Sira.
It was during this period that I got access to the Septuagint texts. Jews don't use them much anymore, even though they are Jewish translations of the Tanakh into Greek. This is when I got to see the various fragments for myself (though most in facsimile format due to the fact that the originals cannot be exposed to handling). Pr458 has spaces with dots instead of the Tetragramaton. I've seen it personally as well as the 2nd generation LXX texts with the Divine Name in Hebrew characters.
The Septuagint is a work of the BCE period, not the CE era. The reason the CBA members were so helpful in my introduction to these tests is that the Catholic Church accepted the Canon of the Alexandrian Septuagint prior to the development of both the Marcion canon and the New Testament canon. It is marked as the "LXX" (which is the number 70 in Roman numerals) due to the tradition that 70 scholars of the Jewish diaspora produced it.
So no, I am not relying on Wikipedia but my own educational training I received after leaving the JWs and my personal experience from my professional life.
Your claim that the LXX is a Christian work from the Christian era is neither substantiated by history or dating of the manuscripts themselves. The Septuagint is well-known as a work of the Jewish diaspora Second Temple era, predating Christianity. Some of the quotes of the Hebrew Bible in the New Testament come from the LXX, which in itself proves that it came before the first century.
The finalized generations of the Septuagint abandoned the use of retaining the Divine Name centuries before the first Christian texts were composed. Because it was used as a source for Tanakh quotes, the New Testament has no use of the Divine Name when it quotes the LXX. This was even acknowledged in the appendix material of the original 1950 edition of the New World Translation.
Because the LXX has those "extra" books like Ben Sira, Tobit, Wisdom, and editions to Esther and Daniel is the reason the Catholic Church has them in their canon. It was the version of the Old Testament inherited by the original Church. The books of Maccabees, products of the Septuagint, contains the origins of the Jewish celebration of Chanukah and are read by many Jews each year on the 8 nights of celebration. These facts alone show the LXX cannot be a product of the CE period, let alone that secular history records when the LXX was produced.
To demonstrate, a copy of the Septuagint (which legend said was owned by Cleopatra) was reportedly lost in the fire set by Julius Caesar's men during a battle which spread to the Library of Alexandria. This happened during one of his famous battles that occurred in 48 BCE. This footnote to history would have been impossible if the LXX was a product of the Christian era.
Again, as I've stated in my previous post, why believe me, a Jew, right? We wouldn't know our own history or details about our own holy books like the Septuagint, or so it seems by the way many Christians and non-Jews challenge us about the details regarding our own culture.