So I am about to jump in and start painting my 1970. I noticed that the underside of the wing has a crack in it. It appears that there is a seam on the underside, and it has about a 6" split in it. I am not sure what those wings are made of. Any advice on how to "glue" it back together? I'm thinking fiberglass resin would be too brittle and crack open again. Any advice is appreciated.