Trying to picture how these attach......
Is it right behind the rear glass window, up and onto roof, (from each side) then these 2 pieces overlap in the middle of roof?
The screw ends attach to the sail panels behind drip rail moldings. I got these moldings years ago at a local pick and pull.
They are most likely attached to the roof with plastic clips like the moldings for 65-66 Dart GT's. It's been so long ago I can't
remember. Look at pics on the internet for reference.