I received a bookplate signed by President George H. W. Bush back in the Summer of 2012. I had written the president a page long letter (I was fifteen at the time), and included his book Speaking of Freedom. I got it back around two months later, with a bookplate inserted that was inscribed (via calligraphy) to me with the President's signature. I don't believe it matches any autopen patterns (nor does it seem to have the characteristics of an autopen), but I would still appreciate your opinions. Thanks!
I can't say with certainty because I do not have a comprehensive Autopen library for GHWB, , but I agree it does not appear to be an Autopen. You typically would not see tapered starts and finishes like this signature has with an Autopen.