Copies from Sinaiticus?

One of the papers presented at SBL was by Robert J. Littman, University of Hawaii: 'Sinai 1 and Sinai 2: Their Place in Biblical Manuscript Tradition'. Littman adopted a 15th century date for Sinai 1 and a 12th century date for Sinai 2 and claimed on the basis of readings shared between these manuscripts and the famous Codex Sinaiticus that these were both copied from Sinaiticus. Now this conclusion, if true, would obviously be rather important since parts of the OT of Sinaiticus are missing and these manuscripts cover OT portions no longer extant in Sinaiticus. If they were indeed copied from Sinaiticus then they would instantly become rather important, despite their late date. At present the sample of readings does not appear to be conclusive evidence. One of the reasons for this is that so little work has been done with LXX manuscripts that we are not in any sort of position to declare any reading a 'unique agreement' with Sinaiticus.

Anyway, here is the preliminary conclusion for Genesis 23:19-24:46:

'Sinai 2 and Sinai 1 have both copied Sinaiticus. All three agree in a few key variations from A.'

In addition to further work on the readings of these manuscripts it would also be interesting to have further opinion as to their date.