Thank for the suggestion, but I tried that and it doesn't work, because the window actually needs a sneaky curve (bend) at the very top and the very bottom to work.

With the help of a really talented industrial designer buddy and his high-tech prototype-manufacturing workshop, we actually created some perfect plexiglass windows like you're suggesting, complete with laser-cut holes for the clock adjuster stick, odometer reset button, and engine service interval reset button.

They were dimensionally perfect, but because they lack the curves, they were a lousy fit.

If I can't come up with OEM replacement plastic windows, my next option is to talk to a plastics fabrication shop who might be able to put the bend at the top and bottom.