Wow. Weird. I suppose in days when it took ages to communicate across the world (if not longer) then it was inevitable there'd be woopsies. Also, in a way, I'm not surprised that a paper would get the author wrong (perhaps deliberately). If Hilton was popular in that era or area, then no one across the other side of the universe is going to know it's not him. Of course, it could just be a local James Hilton (his relatives sell Toyotas locally to me in regional NSW

).
I'm afraid I'm not familiar with the PD or PM9 terms.
Good news about the Foundation being in touch though. You've rekindled my interest in Hilton (I have lots of his books and even a play!) and I think I'll reread "Without Armour" again for the first time in years.