While looking through the digital edition of Codex Sinaiticus, I’ve noticed at least two pages (so far) emblazoned with this stamp:
This screen-grab was taken from quire 35, folio 1 (recto), but I’ve seen the stamp also on the first page of Tobit in Sinaiticus. Since 43 of Sinaiticus’s leaves are housed at University of Leipzig, I take this to be an emblem of that university. Is there a better explanation for it?
Furthermore, what purpose does it serve? Does it simply show ownership? Was the physical alteration of antiquities to show ownership common practice in the 19th century? Did no one think that altering an ancient manuscript might not be ethical? With the Green Collection, its mummy masks, and the (still unpublished) putative first-century fragment of Mark, have handling practices changed all that much?
If anyone adds to these words…
On a lark, I thought it would be fun to check whether a modern editor/handler of Sinaiticus added anything to the end of Revelation. Luckily, they did:
On the page immediately following Rev 22:18-19 and it’s dire warning against adding to and taking away from the words of the prophecy (quire 91, folio 2 [recto]), a modern handler has penciled-in the number “334.” Perhaps the Almighty will be gracious with him or her, since s/he only used pencil and, furthermore, most of the page belongs to Barnabas rather than Revelation!
 See, for example, Josh McDowell’s explanation of Green Collection handling practices: “It was in here that we discovered Mark, the oldest ever: back to the first century. Before then it was 120-142, the John Ryland Papyri [sic]. Now, what you do, you take this mask [chuckles]…Scholars die when they hear it, but we own them so you can do it. You take these manuscripts, we soak them in water. There is a process we use with huge microwaves to do it but it’s not quite as good. We put it down into water at a certain temperature and you can only use Palmolive soap, the rest will start to destroy the manuscripts; Palmolive soap won’t. And you start massaging it for about 30-40 minutes you’ll pull it up and ring it out, literally ring it out, these are worth millions, and you’ll put it back in for 30-45 minutes.” Read more at http://www.bricecjones.com/blog/the-first-century-gospel-of-mark-josh-mcdowell-and-mummy-masks-what-they-all-have-in-common