I put together a sketch of my CMC convertible top brackets and included a page from the manual. The brackets are just a short length of 1" steel angle with one leg trimmed back and a couple of holes. There is a left hand and right hand. Each bracket attaches to a threaded steel piece that is bonded to the back side of the fiberglass. The manual says the threads are 1/4"-20, but mine were 5/16-18. If yours are 1/4", I would drill that hole in the bracket 1/4" diameter (a 1/4" bolt will fit through a 1/4" drilled hole). Also, the manual does not show, but you will likely need a spacer between the bracket and the body to keep the bracket from rubbing. Let me know if you would like more info.
Bob