Honest Feedback wanted

Copyright in Australia lasts for 70 years after the end of the year in which the author died. HOWEVER Works written by authors who died BEFORE 1 January 1955 are in the Public Domain, because copyright was extended from 50 years to 70 years on 1 January 2005, but Australia took the view that once a work enters the Public Domain it cannot be recovered by copyright. Any work of more than one author is covered until the copyright for ALL the authors has expired. This means for translations copyright must have expired for both the original author AND the translator. ALSO adaptations are covered by the writers of the adaption AND the original source material, e.g. "South Pacific" will enter the public domain when Michener's copyright expires, even though that is something like twenty years after the majority of Rodgers and Hammerstein's works. ALSO If a work is posthumous, its copyright protection starts from the year of its first becoming public (either performance or publishing) not the year of the authors death, e.g. the 3 Act version of "The Importance of Being Earnest" is Public Domain, the 4 Act version is still covered. Here endeth the lesson Paul Treasure :-)