I just picked up an almost perfect copy of The Art of Cartooning (1975). The listing on Amazon mentioned several artists had signed the inside cover, but didn’t give any names. Imagine my surprise to find the following:
I think the Gahan Wilson is my favorite, but the Ziegler is a close second.
It looks like this book was purchased at some sort of signing on 5/1/76 by Barbara someone.
Anyway, it was already one of my favorite books of/on gag cartoons, and this particular copy now has a special place on my new shelves.