You said that Qantas isn't flying the Akl-PPT route anymore. In the timetable I recieved yesterdat it says they still fly it twice a week with their planes:

Mondays and Wednesdays QF317 d1735/a2335.
They have a codeshare with Air Tahiti Nui on Fridays QF3343 d1450/a2055.

Did they drop QF317? I hope not because I plan to take this flight next year and then hook up with LanChile to continue to Easter Island and Santiago (LA834).Best wishes for an awesome trip.