These two pages at the very beginning of the book got my attention because of the brown marks which don’t belong there. The marks on the left page show through from the page before and the numbers on the right page where probably made afterwards.
The extract above shows, on the left, a text that makes use of almost the whole page but what is interesting here is the right side. It shows an architectonical plan of a building or several buildings which is represented on a foldable paper. The reader has to unfold the paper to actually see the whole drawing.
In this last spread there are again some visible marks from the pages on the sides. In the right page there are for the first time two columns instead of one, each of them with a different script type.