The above cover comes from a 1976 abridged reprint of the Nevil Maskelyne/David Devant 1911 book “Our Magic.”
As this was 1976, Doug was at his Magic Show/World of Magic peak. So, what better reason to put him on the cover of the classic book? The fact that he doesn’t feature in it at all is beside the point. Doug was undeniably the face of modern magic at that time!