I just didn’t make the connection between the helmet McQuarrie drew and the Inquisitor’s helmet we saw at Toy Fair this year. But there it is! I believe the first rendition of this art appeared in The Art of Star Wars back in the late 1970s. If memory serves correct, it was just a tiny little picture on the bottom right of the page, in the corner, near the stuff showing early Princess Leia drawings.
A thread at TFN has poster “Dark Lord Tarkas” having an exchange with Paul Bateman of in which he confirms the piece is a McQuarrie in essence:
Yep it’s by Ralph, it’s the genuine article. I believe it has seen print before, but not globally.
Ralph was extremely prolific and only a portion of his work has ever been published. He drew a whole bunch of Star Wars material that has never been seen publicly so don’t be surprised if much more shows up. Hope that clarifies things
Thanks for your continued interest in his work, Ralph was a wonderful person.
All the best…