I think there secretarials. Unless he changed his signature in the few years before he died, they are extremely different from his signature when he would sign at autograph conventions, etc.
I am trying to find what I did with my signed copy of Alan Young's book. I bought it through his online store and had contact with the person handling things for him. If I locate I will post it for you. It was a very thin book and I have so many bookcases it could get lost easy. As I recall it was not signed in marker like these and I do not recall it looking like that. I know his old signature the A was very squared. Did you send these through the mail or through the online store?
I finally found my Alan Young signed book. It is a very thin book and got hidden between books on one of my bookcases. As you can see he made somewhat a "squared" "A.