On that drawing the window corners seem to be slightly curved!
Tu. 144 wrote earlier: "Also, despite the plans calling for Redux glue in this area, rivets were installed for some reason that also had their holes punched instead of drilled."
It is my understanding that Chief Designer Bishop specified JUST Redux, but conservative management at de H could not bring themselves to fully trust this new process and material, and went for a "belt and braces' approach.