Hope this helps:
Per the "Australian Publishers Association" @
http://www.publishers.asn.au/index.cfm?doc_id=67 :
If copyright in a work has expired, can you revive copyright by republishing it?Once copyright in a work has expired, it cannot be revived (for example, by subsequent publication). A publisher who publishes a "public domain" work (
such as a work of Shakespeare) will own copyright in the typographical arrangement (and therefore be able to prevent another publisher making an exact copy of that typesetting or typographical arrangement).
However, the copyright in Shakespeare’s work itself is not revived by republishing; anyone can still reproduce all or parts of it.Also (from same source):
How can I find out if a work is in the public domain?
Generally, if you want to know whether a work is in the "public domain" (that is, that its copyright protection has expired), you will need to find out certain information such as who the author was, when the author died and whether the work was first published during the author’s lifetime. There is no list or directory of works that are in the public domain. For more information, visit the Australian Copyright Council's website for their information sheet: Duration of copyright.
How long does copyright last?
This varies according to the type of material. In most cases, copyright lasts from the time the material is created until 70 years after the end of the year the creator dies. For more information, visit the Australian Copyright Council's website for their information sheet: Duration of copyright.
