Kathy McCormick left this question in a comment on the Typography post:
I have a friend that has been trying to figure out what year this Cadillac emblem is from. I have spent hours on the web trying to help him out to no avail. Maybe you can help. I’m thinking the style looks like something popular in the 20′s or early 30′s but that is just a guess.
I usually make a point to look up and answer these kinds of questions myself, but I’m running a bit late tonight. Anyway, it’s worth just looking at if you don’t know the answer, Although I know someone will.