I once heard from a Sofer the shocking revelation that Rabbeinu Tam's Tefillin do not actually follow Rabbeinu Tam's opinion. Is that correct? Did I misunderstand? Are there any Soferim in our forum who are not only intimately familiar with how "Rabbeinu Tam Tefillin" are made, but also intimately familiar with Rabbeinu Tam's actual, written Shittah?
In addition Rabeinu Tam holds (see Bais Yosef (3rd from top)) that the word Letotofos in the Parsha Vehaya Im Shomo'a is written without any Vov while we write it with a Vov after the first Tes even in Rabeinu Tam's Tefillin.