I've observed that Clark Gable's autograph remained pretty well consistent over the years of his acting career except for the way he formed the "G" in his surname. 1930's "G" always looked to be more rounded and almost looks like a number "9" while WWII era and onward "G" had sharper lines and open at the bottom.
I just stumbled upon a document from 1946 in which Gable consents to have his signature attached to some fundraising activities for The Motion Picture Relief Fund. Both styles of the "G" are on this document in two separate signatures. All of the other letters look the same on both signatures.
I wonder if he just switched back and forth with the "G" in his post-1940 signing... and why?