I did some more body filler, mostly little bits in places where an earlier application wasn’t quite right. The roof panels and some dinged areas around the rear quarter windows are almost there.
I also bought some good made-in-USA chicken wire for the foundation of the roof area.
I also bought a piece of fabric to serve as anti-squeak materiel between the roof ribs and the chicken wire. I cut it into long 1-inch-wide strips and glued a strip to the top of each roof rib.
Finally I bolted the roof ribs into place. I had fitted them, drilled the holes, and bought the hardware a while ago, so it took just a few minutes to install them.
Now it is no longer possible to stand up inside the car and work on the roof from inside. But after I install the chicken wire, I can mask the roof opening with plastic sheet for priming and painting, without having to worry about the cat trying to walk on the sheet and fall through it…