Here for your consideration is a very rare Mint UNC Very Last Prefix ADK Australian Paper $20 banknote. Derived from the very last batch printed.
The note offered here is even rarer as it includes a Limited Edition No.2347 of of less than 4,000 Printed in Black OvPT. It celebrates the 100th Anniversary 1893-1993 of Hargraves famous box kite experiment, an innovations in Aviation at Stanwell Park South of Sydney in 1893. Nicely exhalting the aviation theme of the old $20 Australian paper banknote it has Sir Charles Kingsford Smith, the early Australian aviator on the reverse of this very last side-thread & OCRB machine readable serial font type $20 banknote.
The change from center to side thread on later paper issues was done to increase the longevity of paper notes during circulation, with the later font change from Gothic to OCRB incorporated due to advent of machine note count readers from 1979 onwards. This very last batch of $20 paper issue notes replaced by polymer issues from then onwards.
A great time to invest in this note as it will only increase in value steadily.