I’ve always had trouble getting roofs to hold together whille the glue tried to dry. Clamps never seemed to work too well, and they’d often slip or leave gaps along the apex of the roof.
Was at HF this weekend and found clamps for doing corners. Not 90 degrees, buy any angle. They adjust! I bought two of them to clamp each end of the roof simultaneously. It still gapped in the center, but using another clamp in the center made the roof solid! Now when I’m rebuilding old buildings, the roof will come out perfekt!