I always thought it bizarre that the De Angelis brothers choose this name as a pseudonym for their music. When I read the name Oliver Onions I think first of Bud Spencer and Sandokan and not of the writer. Nobody in my group back then knew Onions the writer. But millions knew Oliver Onions the musicians.
Only in the mid-80s there were two books with stories and maybe novels, I don't know, translated as mass market paperbacks, in an imprint of classic phantastica.
I have to confess that I never read one of his stories.