I have a Sphere "paperback cover proof" with the withdrawn ISBN number that has been posted here. The cover art is completely different as well (an awesome graphic painting by Steve Crisp). I do not know if the finished product was published (and quickly recalled) with this cover though, since I have never seen a copy.
That cover painting references the ending of the Robert R. McCammon story. The protagonist hitches a ride in a VW van trying to escape his fate, but it comes to life and devours him. (Though I would imagine the author had an earlier model VW van in mind, not one from the 1980's.)
I love the idea of this freelance editor overstepping the mark ("Well, that's a shit ending. Let me improve it"), though would not be the least surprised if some of our authors tell me it's no big deal, happens all the time.
No indeed! Thankfully, it's rare, and Nick Webb was so appalled by the behaviour of "this miscreant" (as he put it) that he ordered the edition destroyed. My tale was eight pages long and the unnamed culprit made over a hundred changes.
I have never seen the "van" copy of the book, though I own all of the other editions (I run Robert McCammon's website and collect all of the editions I can find). I'd love to get a copy, obviously, but in all the years I've been collecting, I've never seen one. I do know that the bit about the stories being rewritten is true (as Ramsey has said). Somewhere, I have a document of the changes that were made to the McCammon story, done by someone who compared the Sphere paperback to the U.S. edition. I'm pretty sure he was working from the "skull" cover, but that was a long time ago. I'll have to compare them sometime....
Funny. I see now that left pretty much that same comment on Marty Halpern's blog back in 2011. I had forgotten all about having done that.