If this is supposed to be from the 1st century or thereabouts, then something is fishy here. It is my understanding that the “books” were papyrus scrolls of that time, not the sort of leaved lead pages we see here. I think codices came later.
I would think people then could have used many different formats. They were smart people and could have easily used a format different than the normal papyrus or animal skins.
I want to hear more about this story.
Potentially very exciting if these are genuine.
The Romans were linking wax tablets in this format for quite some time before Christ. It's not inconsistent with the era, although I believe most Jewish texts were still maintained as scrolls.