Martha wrote last Fall about Frankenplan, and now we have Frankenbook in the lab.
It appears that the torn bookcloth was mended by machine before it was used to bind this book. Have you worked in a bindery? Do you know what’s going on here…?
Frankenbook
Library and Archives Preservation 
Well, so happens that the cloth was put on the roll during mfg they stitched it together to make the roll longer (or some such thing). I’ve come across two examples (the rolls that is) here at Syracuse. The first was a roll of Joanna D-grade buckram, the other LBS’s heavier cloth. When the cloth was sheeted for covering, they just used it anyway. Cloth grain probably runs the wrong way on that book, and at least two others (to get to the 42″ish roll width…). Would have looked cooler with the scar going across the full cover…
Thanks for the explanation, Peter!