Hi Rick and JJ,
I am no authority by any means, but I also have a vintage airstream that was missing the rock guard. I looked around and asked many questions - mostly I learned that even if you could find a vintage rock guard, it would most likely be too brittle us be of much use as I believe they were made of plastic. I've read that, if you're handy, you can make a rock guard by purchasing the glass and welding the frame...but we're not that handy.
We finally bit the bullet at purchase one through Inland RV
. Well actually, we didn't have much choice since we lost the front window traveling down the freeway on our way to the NorCal Rally earlier this month! Fortunately Inland RV wasn't too far away and they did a great job of installing it.
It doesn't have a vintage look, but I personally don't think it detracts from the charm of our trailer. Plus, it's kind of nice to be able to see through the window while we're trailering, as Wally intended. I'm attaching a picture.
Hope this helps a little! Good luck!