Lee, you can still purchase a gravel guard (and hardware) from Scamp
. I did. Just be aware, it's a piece of FLAT fiberglass. Under tow the wind bends the fiberglass to the shape of the window. I think only those that buy at the time of new manufacturer actually get a curved gravel guard... and I can't be certain about that.
If I was to do it over, I'd purchase stainless steel hardware. But, I keep what I've got waxed and after 7-8 years haven't seen a sign of rust. There's plenty of threads where folks are asking about how to get the rust off the gelcoat from rusty hardware.
Best of luck