I just ordered one from Vintage Trailer Supply, they may be able to help you out. They have a lot of parts for vintage Airstreams and others and do sell those Gards, I just ordered one for my 1964 Globetrotter. Here's the link to it: Fiberglass Stoneguard
Keith, I have no idea if they are the same...or useable, but I removed my sliding supports and replaced them with gas pressurized tubes. I have no use for my sliders. PM me with pics and dimensions. They're yours, if they will work.
"If the women don't find you handsome, they should at least find you handy." - Red Green