This first spread stood out to me, because of its random placement in the book. You would think that the text has already started, but then suddenly on page 52 there’s this abstract. Wouldn’t you put that at the beginning or the end? I then also noticed, that the pages before and the ones after the abstract are counted differently: In the beginning there’s combinations of letters on every page like xix or cij. But all the pages following the abstract are then counted in Arabic numbers.
What you can see on the second spread, is something you can find repeatedly throughout the whole book. It’s a glued-in leaflet, mostly with drawings or plans on that need a bigger format than the book provides.
The last spread I choose because of its layout with the empty page on the left. It appears multiple times in the book. I thought it either is to write down personal notes, or to trace the drawing from the previous page and maybe add own interpretations or adjustments.