Look what I found in the library. And it really is this edition.
The library acquired it on 20th November 1968 (there's a date stamp). And it still has the old style pocket for the library ticket. It seems to have been borrowed on a regular basis through the 70s and 80s.
Then the library went digital, and there's someone's receipt tucked in the pocket dated November 2014. I wonder if that was the last time it was borrowed.