Based on what I know of the collective CASA mentality, a decades-old SCPL that has not existed in their living memory won't be recognised. The deadline to convert old CAR 5 licences has now passed, so even if you had an old Aussie ATPL you are SOL.
It would be easier to simply convert a current ICAO ATPL. There are a few hoops to jump through, but nothing that money and study can't solve. The ATPL flight test counts as an IPC, takes about 2.5 hours and can be done in a simulator.