I was toying around with making one, since I had the rifle base only.
I got a pretty short one from someone else here, and it works well, but aims all the wind right at my head. Very loud.
Anyway, wanting a taller screen I got a cheap piece of acrylic and had at it. Its just a hair under 19" and is very quiet. I am looking thru it. For me, it should probably be closer to 17" with my Corbin, but it will make a nice cold weather shield.
What Ill most likely do is get a GL1200 sheild and make one from that, and add the GW vent to it.
Lots of cool air when I want it, not much when I dont sort of thing.
Its worth experimenting though, if you have the time. You really do get a good idea of what size works good for you with not much cash outlay. I have $16 in the big shield I have now....