Actually, I couldn’t find it! I paged through all my subscribed threads CTRL+F’ing every variation of “Dead Sea Scrolls”, “Masoretic text”, “Ancient versions”, “manuscripts”, “textual criticism”, “Qumran”, “Biblical scholarship”, and “Septuagint” that I could think of… I was pretty far off, titled “Glaring Errors in the Douay-Rheims?” - no wonder it took me five months to locate a reference (O! how I dread my dissertation now, although I’ve begun the habit of citing everything as I write it, instead of trying to go back and find the references later if I’m called out).
Your bump brought it back to my first screen again (I’m subscribed to about 1,100 threads); I found the answer spread through several books and articles (although it is not true for all parts of the Septuagint, as some books in the DSS and MT agree with each other more; whereas some agree more with the LXX), so I’m going to have to give quite a bibliography (I believe my initial recall was tainted, and the claims are not as strong as I had supposed - indeed, little agreement in Isaiah 7:14, much in Isaiah 53, most in the deuterocanonicals - after half a year of searching - I begin to think that some of it came from reading a translation of the DSS at the same time as reading the LXX, noting some similarities and conflating differences - however, I did find the original book), which is (apologies for the confused nature of the citations):
James VanderKam in McDonald and Sanders (eds.)
The Canon Debate,
Questions of Canon through the Dead Sea Scrolls (pp.90-104, p. 94), which cites 25% MT, 30% LXX, 40% Samaritan, 5% unaligned.
Those mentioned above in the
Biblical Archaeology Review:
Moises deSilva,
Introduction to the Septuagint, pp.99-109 (and more, about how the LXX includes - or MT excludes - some Hebrew/Aramaic books found at Qumran, such as Tobit, Sirach, Judith; the entire book is good reading).
Edwin M Yamauchi,
The Archaeological Background of Esther, Parts 2 and 3,
Bibliotheca Sacra, Issues 2-3, 1980.
Harvey Minkoff,
Searching for the Better Text, Biblical Archaeology Review
There was something written by Charlesworth (of Old Testament Pseudepigrapha fame), but I can’t even find the reference to the reference now…
And some textual notes to Samuel in the NRSV and NET Bible, which, again, I was certain was in a book by Metzger, called something like
Textual Notes to the New Revised Standard Version.
When you’re done with those (which are available without a pricey subscription) I’ll send you some more (most of which require a subscription, or access to a library with one: I don’t have a scanner, but I can attempt to take cell-phone pictures of the relevant pages… they’re still legible [and that’s with a Samsung Galaxy SII], just not fun to read).