Been looking at FlightRadar24 regularly of late and the NLK-AKL return service with the Nauru Airlines aircraft still seem to be operating each Saturday.
Re:
Way back, 1978, Nauru had its own register, C2-RN?, have they given that up now and become Australian registered?
A bit of research shows that Air Nauru got an Australian AOC back in 1998. Since then some name changes to Our Airline and then, more recently, Nauru Airlines.
Interestingly, it is a foreign airline holding a full Australian AOC, not a Foreign AOC as most of the foreign international operators do.
Just got to love Wikipedia.