Dragonheart,
One thing no one asked. What was the original "weird" covering surface that you were told wasn't fuel proof? I'm guessing that it was one of those that's been pre-printed with panel lines and rivets, but.... Let us know. The more info you give when asking questions like this, the better the answers you'll get.

Right now everyone is assuming that they know what the original covering was, but if they're wrong, their advice may be BAD! So be careful.
Dennis-