I'm no expert, but I have done a Finance Masters - in which we...

I'm no expert, but I have done a Finance Masters - in which we covered Tax Law for 1 unit. From my own understanding, CGT discount (50%) applies when the transaction takes place. If money changed hands & contract to enter into purchase was entered over 12mths ago, the discount applies. Doesn't matter that there is a change of name or anything, it is still the same company - hence it would apply.

But this is IMO - seek professional advise