CGT on shares acquired 1985 - 2005 & periods of non-residency

A new financial year and time to consider possible share sales/acquisitions/re-balancing of portfolio etc. In the mix are some shares acquired in the 1985 - 2005 period.

There is no CGT on shares acquired before CGT was introduced in 1985. In December 2006 the concept of electing to treat shares as "Taxable Australian Property" was introduced, so that residents departing Australia could pay the CGT up until the departure date and then the shares would be CGT free until the owner was again a tax resident.

What happens to shares that were acquired by a tax resident between 1985 and 2005, and the owner departed in early 2006, before the "Taxable Australian Property" election was introduced? A further complication is periods of residency/non residency since then. Another complication is that some are Australian shares and some are US shares. Do you get the 50% discount only for the periods of Australian residency? Any difference in tax treatment between Australian and non-Australian shares?

Could someone point me to the correct information? Most info I've found seems to only cover shares acquired since 2006 or before 1985. Thanks!