George is right on about the potential problems fitting a different door. Fitting a window and hardware would be easy. I'm pretty sure the window from a 172 would fit.
Did you ever look to see if your door has the recesses for the window hinges? You might have to take off the inside window trim to get a good look.
I'm not sure but I think the door hinges are different on the 172 which is what makes ours so rare.
window frame
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