Recently, I was enjoying the following: Theodore Skeat, "The Codex Sinaiticus, The Codex Vaticanus, and Constantine," _JTS_ 50/2 (1999) 583-625. (I found out about this article from James Snapp Jr's post, no 6307 on this fine list.)
Skeat was quite convinced that Sinaiticus was written in Caesarea and was irritated that scholarship had so far ignored the "almost incontrovertible" argument in support of that assertion put forward by Herbert Milne and himself. Skeat goes on to remind us of another thing Milne and himself wrote about, namely the similarity of Sinaiticus Scribe D and Vaticanus Hand A: "it would be hazardous to argue identity of the two hands ... but the identity of the scribal tradition stands beyond dispute." (_Scribes and Correctors_ (1938) 87-90) Skeat says in the JTS article (603-4), "I do not think there can be the least doubt that _both manuscripts are the work of the same scriptorium, and--which is just as important--were written at approximately the same time. Vaticanus therefore, like Sinaiticus, was written in Caesarea._"
Skeat's theory is a big deal, and eminently sane. Now to my crazy idea. Given today's efforts with respect to these two manuscripts, might we hope to find some inky fingerprints on their pages which might confirm that the same individuals worked on both? (I'm thinking of a painting bought for $5 at a garage sale which some say looks like a Jackson Pollock. On the back is a fingerprint that some say matches prints on that might be Pollock's.)