It's incredible - either he's schizophrenic or he has scribes working with with him at different times. I don't see how one person could be responsible for three different handwriting styles on a single page! And the handwriting in the book as a whole has countless different styles and variations. It's utterly amazing but certainly the person who was writing from 299 - 343 in the folder Επιστολαί τινες προς φίλους Καλλινίκου πατριάρχου Κωνσταντινουπόλεως is the author of Mar Saba 65. I will bet anything on it ...
Also in the same folder Επιστολαί τινες προς φίλους Καλλινίκου πατριάρχου Κωνσταντινουπόλεως the same author wrote from p. 3 - 8 it starts to become strange again for the next few pages (I am not sure if it is the same author - look at the lambdas in particular). Then at p. 10 we're back to the handwriting of Mar Saba 65 until the end of p. 14 (where everything has to get crammed into the bottom margin of the page). But then look at p. 15. What the hell is that? It's another handwriting style completely. It's related to the Mar Saba style. It might even be the same person but ... Wow. No wonder no one made the connection between Callinicus and the author of Mar Saba 65.
Notice the single and double stroke lambdas in this new writing style.
Stephan Huller has had a life long interest in religion and spirituality 
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."