Tony:
By the time we finish with David's lessons on how to identify the various permutations of these trucks he is going to wish he had never asked the question
I am going to try to pay him back for some of his 4 pagers with a listing from the AEDB book on what to look for.
Reminds me of some lists I made up, and lost, of ID tips. One I do remember is the difference between 1939 and 1940 Chev commercial trucks. The 1939 has 17 vertical bars in the grille and the 1940 has I think 12. Then you have to look at the badge on the grille if your photo does not allow you to count grille bars and determing the size of the lettering. The easiest tip was that the 39 had no park lights on the front wings and the 40 did but in practice many of these lights were removed or damaged and taken off so you had to go back to counting grille bars.
Next, we will have him counting rivets in the bodies.
Bill