I have just been refreshing my memory of the Australian Copyright Act 1968 (as amended to the end of 2005) and I can't readily find any transitional provisions removing the extension to life + 70 (as per S 10) from copyrights that expired before S10 was amended to life + 70 (of course in 1968 it would have been life + 50).

This may be careless Saturday morning looking, of course.