One only has to look at the science fiction field in the 1930’s and 40’s to see where Hubbard got the inspiration for OT III. The space operas of that era were full of stories about galactic ruler, revolts, and such. In the fantasy magazines, like Unknown, where Hubbard’s stories were sometimes published, we find wandering spirits, condemned spirits and the like. It was not a great leap for a mind like Hubbard’s, to talk about brainwashing thetans.
Busty women were par for the course on covers. Teen boys and young adults were the primary buyers so the artists played to that audience. Many a teen boy must have felt a tingle when looking over the drugstore magazine rack and seeing such bra-busting beauties!!