I still kick myself to this day. Back when I first purchased my original copy of The True Art and Science of Hand Balancing by Paulinetti and Jones they had another course on head balancing. At the time I was only interested in doing handstands so I only got the one book. Since that time I have never seen another copy of the head balancing course offered even though I’m always looking.
While the regular headstand with the use of the hands is an easy stunt just about anyone can do, doing it without your hands is an entirely different matter. It takes tremendous balancing ability throughout your body. Here is a photo of Rafael Guerrero balancing on his head in good style.
I think the best way to work up to this stunt is to start with your hands and slowly do away with the fingers, similar to an approach you’d make with the one arm handstand.