A real problem is posed by the foldouts. Why are they there in the first place? Did the author only have some leftover pieces of vellum that could not be cut to the proper size? Then if so, shouldn't they be at the end of the book (either physically, or [chrono]logically)?
According to the digraph statistical analysis I once did, the text characteristics of the text on the foldout pages marks a transition from A to B language. {Since Currier largely used the text on normal pages for his analysis, he found the two distinct sets which he called A and B.} So also in this context they are not the 'end' of the document.