I was thinking more along the lines of tempered glass,Rayce but 'oldblu49' is right. A good glass shop could cut you one from Laminated glass. They may be able to get you a tempered one made if that's what you would prefer.Have you got the old glass as a template?
I'm personally not a big fan of laminated glass in doors,but hey,maybe that's just me!
Jock.

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.