Thanks for pointing out the work of Tov. I found this interesting:
http://www.lectio.unibe.ch/05_2/troyer_names_of_god.htm
Many introductions to the Hebrew grammar will explain the phenomenon that the Name of God is not to be read as it is written in the text, but as it is supposed to have been written in the margins.[6] Indeed, in the Hebrew Bible, more precisely in the Masoretic text, the consonants of the Name of God are written (Ketib, hwhy), but not pointed with its presumed vowels (hFwOhy:). The vowels that are added to the consonants of the Tetragrammaton are the vowels of the word “Adonai” (ynFd$)j). When the Masoretes wanted the readers to read a word differently from the one written in the text (the Ketib), they notified the readers of the different reading by attaching a circellus (a little circle) on top of the Ketib, and by writing the related word, which should be read instead of the Ketib, in the margin.
This situation, of course, sounds ripe of confusion.
Se also:
The Wadi Daliyeh papyri offer also evidence for a two-letter form of the Name of God. See, for instance, WDSP 15, p. 104, line 2: Deliyah, the last part is the two-letter name of God, written YH.
And how would YH have been written in Greek?
The shorter forms of the name of God seem also to be pronounced independently of personal names. The Samaritans thus seem to have pronounced the Name of God as Jaho or Ja. That the shorter names of God were pronounced is also mentioned by Theodoretus. In his work on Exodus, more precisely in Questio 15, he speaks about the pronunciation of the Tetragrammaton. He states that the Samaritans pronounced it Iabe/, whereas the Jews pronounced it Ia.
In this Old Greek text of the Book of Leviticus, the name of God is written IAW. Skehan, the editor of the text, suggests that the reading IAW is more original than kurios: “This new evidence strongly suggests that the usage in question goes back for some books at least to the beginnings of the Septuagint rendering”.[40] That the name of God was simply written IAO in the Leviticus scroll is very telling, for it is precisely in the Greek Leviticus scroll that one reads about the prohibition of naming the Name of God! IAO can be seen as a transliteration of YAHU, the three-letter form of the Name of God.