This is fascinating Reading! I have chimed into this post somewhat late, but for what it's worth, this is what I have a record of, could have a few others and will check and add to the list if/when I find them.
[Numbers added to the lists. Thanks! --BWJM]I have the 2nd and 5th edition of the Charlton Guide. The 2nd edition was published in 1987 and there is no mention of the AU_ series as of that edition. The 5th edition notes the AU_ series and anomalies. I am missing the 3rd and 4th editions (and the 7th edition). Which edition first makes reference to the AU_ anomaly?
{{Aside: Also, if anyone has the 3rd, 4th or 7th edition for sale/trade, please let me know. I have the 9th for trade if interested.}}
This series has always interested me, but the notes were so scarce to find (even in the 90's) that collecting them has always been a challenge. I wish you all luck with finding an AUG/AUH/AUJ T/C in a dealer's junk box!
Mark