I wonder if that's his real, everyday signature, or if he just didn't want to make his real signature public due to worries about identity theft?
This is a job I wish they'd give me, but since it is unlikely, I posted my ideas on my blog. "The Treasury Secretary and the Calligrapher: "Dear Jack, I can help you sign that dollar....."
http://alphabetroadtrip.typepad.com/alphabetroadtrip/2013/01/when-handwr...
And you can see an excerpt at my typophile blog.
