When I bought my first house, they REQUIRED me to sign my full name, not my legal signature, including the "jr", which I never use, It is odd. They required the same thing of the 20 year old Hank in 1941. That is not necessarily his signature. It is a cursive writing of his name. My legal signature looks like a big loopy BRRS, but for some companies and government agencies, that it not good enough. I'm not sure how they would handle it is I was illiterate. An X used to be good enough for a signature, not requiring someone to write out their full legal name in cursive...
You could tell how they were busting his balls in the way that they made him write the address. Notice that he wrote L A, CA and they make him write "os ngeles" next to it. ha!