i found the email message i mentioned, from 1994, and the relevant bit said

	The Oxford English Dictionary, 2nd Ed., that goes with Plan 9 "dict" came
	from a tape that Bell Labs acquired for linguistic research, so we
	cannot redistribute it.  The Bell Labs researcher who obtained it says:
		....
followed by a brief description of how the material was obtained from OUP but the process
did not seem to be easy to repeat.  there was a contact email address but if
i did follow it up at the time--i cannot remember--i am certain it did not get me the data.