I just traded my half doors and soft top for CJ hard doors and a CJ hardtop. I had to notch the outside corners at the front to fit around my rollbar (YJ). The top had/ has a crack in the front corner. When I notched the material "melted" as I cut it. Is this fiberglass or some other material? Thanks for any help! I want to buy the correct repair material, just not sure what I have. Thanks!