Frederick, you got me. I thought that Scale Mates time line page showing the history of a kit linked it all, but I don't always put my glasses on to read stuff.
I could not really get a good look at some P-40 data to clear up the rear window area that you were talking about. I was under the impression that they changed as the a/c progressed in series, but still could not find that smoking gun. I appreciate the help I need all that is offered.