Here's a couple of photo's of a custom rock guard on an Airflyte. Looked to be a really good solution. The owner of this one also made a vinyl cover for the front wall to prevent chipping also as he covers a lot of miles.
AstroGuard hurricane fabric ( link 1 ) its not vintage but I'm going to use it for my rock guard. some screen framing ( 2nd link ) and corners (3rd link) its got to be super light and strong to meet the Fla. code.