Still no LXX

Yesterday, I posted some brief reflections on a tea break conversation I had with Peter Williams, the warden here at Tyndale House – The LXX doesn’t exist. Let me begin by saying that I didn’t even begin to fairly represent Williams’s arguments; he had a few other points which I forgot, including linguistic arguments (you’ll have to wait for his book.)  Also, this issue is way “above my pay grade” (to use an infamous quote from someone we all know.) But it has become a teachable moment for me, and I appreciate the responses.

Jim West took this schoolboy out to the woodshed – The Madness of Good King Ben saying:

  1. You’re full of nonsense, plowing the seashore, etc.
  2. Spell Rahlfs right.
  3. Oh – and read mogens muller on the subject
He says:
First, there’s more than enough textual evidence to support the existence of a collection of Greek texts which were translations of Hebrew texts later called the Septuagint and the Hebrew Bible respectively. (Emphasis mine.)
I mostly agree except that I might prefer to say “collectionS of Greek texts” rather than A definitive collection. We might also mention that manuscript evidence of certain texts does not necessarily constitute evidence of the collection – only certain elements of it. This remains true even as we claim, along with Muller, that basis of of the canon had been laid, “long before actual canonization took place.” (Mogens Muller, The First Bible of the Church: A Plea for the Septuagint, JSOTSup 206, 1996, 25 – See RBL Review). Note that I’m not trying to make any particular claims about BHS as over against the LXX, which seems to be Muller’s main concern. 
It is a question of two processes running partly parallel, and it is no longer possible automatically to give priority to the current Hebrew text (104).
Unfortunately, the main point I would have wished to get from Muller – more detail about the nature of the pre-Christian Greek text (with dates?)- is largely sidelined in a pair of footnotes (43), which say that the targums are dependant on the Septuagint. (I theoretically shouldn’t have any problems with that). Even he says,
“the Greek translation may reasonably be seen as evidence of a process reflecting changing traditions which only gradually came to a standstill once a particular Hebrew text became normative.” (italics his, sorry, I lost the page number somewhere around 30 or 40?)
[Much later] In principle only canonization can give traditions their final form (121). [See also Doug Chaplin’s The Bible doesn’t exist?]
[I confess that I moved through Muller pretty quickly, but I hope I captured the gist of his argument; I’ll have to come back to him later, he’s giving me a lot of food for thought. Thanks for the heads up, Jim]. In light of Muller’s arguments about canonization, his comments about the tumultous history of the Old Testament Apocrypha (39) seem to call into question the very idea that NT writers used “the LXX.” 
Ah Ha! Here it is!
. . . some of the Old Testament quotations found in the New Testament which cannot be explained as originating from either the Masoretic text or the Septuagint may derive from a Greek translation depending on a Hebrew text which was not identical with the Masoretic text (Muller, 114; emphasis mine.)
In other words, we have something other than the Septuagint – not the LXX as such.
I’m not questioning that all the books existed in Greek translation before the New Testment period. I also have no problem agreeing that the primary Bible of the NT writers was in Greek. My question is, can we accurately call what they used “the LXX”?  
I suppose we can refer to Greek translations of the Scriptures in Greek as “the LXX,” as long as we recognize that we are being somewhat anachronistic and don’t assume that it was “the LXX” as we know it. As Jim points out, New Testament writers might have been using a textual tradition now lost (or traditionS).
Please carefully note: I am not saying anything about the historicity, authenticity, inspiration, canonicity, or authority of these books. (No Bart Ehrman ;-). 
I’m also not the only one who thinks there is no LXX. Jobes & Silva – Invitation to the Septuagint:

Strictly speaking, there is really no such thing as the Septuagint. This may seem like an odd statement in a book entitled Invitation to the Septuagint, but unless the reader appreciates the fluidity and ambiguity of the term, he or she will quickly become confused by the literature. . . 
. . . [The Septuagint, was produced by many people unknown to us, over two or three centuries, and almost certainly in more than one elocation. Consequently, the Greek Old Testament does not have the unity that the term the Septuagint might imply.]
(page 30; cites Leonard J. Greenspoon, “the Use and Abuse of the Term ‘LXX’ and Related Terminology on Recent Scholarship,” BIOSCS 20 (1987): 21-29.
David Hymes has also helpfully provided some other good quotes and bibliographic references in his The Septuagint: Some Dating Stuff. That might be a good place to start: (I admit, I had to google to find out his name.) Or you could go here.
I’m only asking: “Can we accurately say New Testament writers are quoting “the LXX?'” If not, what should we say? Here here are a few possibilities for starters: They are quoting . . . 
  1. Moses, Isaiah, etc.
  2. the law, the prophets, and the writings (Tanak)
  3. Scripture (even “The Scriptures”)
  4. [All the above] in Greek; Greek translations of [1, 2, 3]
  5. What we formerly conceptualized as “the LXX” ;-).
  6. ???
Okay. So I’m in way over my head. Somebody help me out