Like the front windscreen, I am using windows from Cee Bailey’s for the rear windows. As I received them, they were pretty close, but did need to be trimmed down a bit (like maybe 1/8″ in a few places).
The window flanges in the cabin top also needed a bit of work. There was junk from the molding process in the flange, so it took a little work with a drum sander on a dremel to smooth everything out and leave a good level mounting surface. But now, the rear windows have been sized.