Thanks to all for the information so far.
I’m thinking of concentrating on each “difference” one at a time. Trying to be sure to get it correct and get the years correct. Right now the parking lights seem to be a good place to start.
Hear is what I have so far:
I believe the ’41 units were not ready for production in time so parking lights from a ’38 or ’39 Pontiac were used. The ones that were on my ’41, when I got it, were made up of a zinc (pot metal) cast base and a stamped sheet metal cover. The light bulb was on a bracket that held the bulb in a horizontal orientation. Also the lens is 4 inches long.
I can provide photos of all of this stuff, but will need photos of the individual components of the parking light assembly for the later years. We should also get some conformation that my assumptions above are correct.I suspect that if a number of bolters agree that would do as conformation.
I’ll keep filing all the other stuff as it comes and post the progress here so please keep sending what you have.