Ute rear window dimensions

I'm hoping someone out here can help me figure out the rear window dimensions on an AP6 ute. I'm working on converting my 66 Dart wagon and would like to get the correct dimensions to have a piece made here in the states.
I've been looking at them and that glass appears almost .....ALMOST flat. I'll be danged if I wouldn't MAKE it flat. Then it would be real easy to have the glass cut for.