Over on the blog for my current research project (The Early History of the Codex), I have written a series of posts about making a model of the Beatty-Michigan Pauline epistles codex (P46).
Making models is always a useful exercise, and that was certainly true in this case. There are three posts that address different aspects of the process:
Making a Model of P46, Part 1: The Size of the Bifolia
Making a Model of P46, Part 2: Missing Stays
Making a Model of P46, Part 3: Papyrus Codices, Spine Strips, and Covers
Variant Readings 
Excellent practice!!
Very interesting. Regarding the protruding pages due to it being a single quire codex, do we think trying to remove this unaesthetic look is the reason behind P45’s (Chester Beatty 1) single-page multiple-quire codex? All single pages (before and after being folded in half) would therefore be the same size, not require any sort of calculation for trimming, and probably would’ve remained closed a lot easier with one on top of the other, with the top pages weighing on the bottom pages. Due to the size of the text which was trying to be fit into P45 (Matt-John-Luke-Mark-Acts), am thinking this would work better as a format than single quire.