I ran into a similar problem with the sail panels on my '69 Mach. My sail panels were long gone, but both retaining clips were still installed in the appropriate holes in the sail panel area. I searched high and low trying to find a set of sail panels that still had the original metal retaining rings, but came up empty. I finally ended up going with NPD's "better" repro. Those sail panels are thicker, and have the metal retaining rings for the lights already installed.