Well Rusty,
I went to the valiant and opened up the area of the sail panel and it's junk for even a pattern. But it looks like some heavy posterboard is all it is. It fills in the area from under the two screwed panel, to the upper edge of the window. It looks like it was spray glued to the metal and clamped with the panel as i said before, no other mounts that i could see. I'll post the pictures and i hope it helps. One other thing it follows the shape of the whole metal area all the way to the back glass rubber. It looked like the headliner material folded around it and was glued in place. ?