I sent a note to Jon C. Rogers over the weekend and already I've heard back. He replied that he quite liked what I'm doing with the designs from The Spaceship Handbook
and that he would forward my letter and the images I included to his co-authors.
I also asked him if he had any idea as to what eventually became of the full-size exterior of the Flash Gordon rocketship and the companion filming miniature. I'm waiting to hear back.