Nice to know you retain such faith in me Brian, even though my own Arthur Smith Prize is from a more recent, less challenging era! (I shared it with John Whitley in 1965 as I recall - We both returned to Oakbank that autumn for the speech day presentation.) I've still got the books in fact, complete with labels inside which look more or less identical to the one in your recent discovery.
On the subject of academic content, I know it's fashionable to knock contemporary standards with terms like "dumbed down", etc., but have to admit that what I teach for A-level today is mainly stuff we encountered around year 3 or 4 (and then with as much of the maths removed as possible!) Today's A-level candidates just wouldn't have a prayer if faced with a 1960s O-level paper. It's not their fault of course - some are very bright - they're simply being denied access to any worthwhile knowledge during the years of Comprehensive Secondary education.