Further poking around comes up with an article that claims the story originates with a consultant friend of Russell Ackoff (the author of the book I linked to),

Further poking around comes up with an article that claims the story originates with a consultant friend of Russell Ackoff (the author of the book I linked to), and took place in a New York hotel in 1955. A bit more specific, but I'm still a bit suspect since Ackoff doesn't seem to mention these details in his writing. Presumably if it is mentioned in the earlier book that you point to, Ackoff must have published or mentioned it elsewhere. I've done this one to death now, so I think I'll move on.