Ya know, I keep seeing these kinda requests ... and then somebody posts how they found one on Ebay and it was all grungy and they had to sandblast it and repaint it and ...
As far as I can tell, a piece of square metal tube and some flat stock, and you culd easily make your own. You'd need a welder, or to find somebody local with a welder, shouldn't cost much.
If you were local to me, for instance, I could easily do the welding for ya, and it would cost you, say, a 12 pack of Henry's Rootbeer (I don't drink the alcoholic kind.)
Alternately, maybe I should claim these are hard to come by and start making them myself =))
I mean, you just want it to clamp onto the window rails, yes? Or do you wanna drill into the roof of your truck?
My '74 has no roof for me to attach one, and my '85 is staying stock (CUCV), or I'd have made one to show you pix of by now =))
-- A