Qantas currently has 11 Boeing 747-400s remaining in service. The oldest of these was delivered in 1991, and the youngest in 2003, making it only 13 years old. None of the 747s currently in service with Qantas are 30 years old.
Of these aircraft, 9 were recently refurbished and contain new A380 style seats, IFE and interiors. I find these aircraft a pleasure to fly on.
Two have not been refurbished, and I suspect these are the aircraft you are referring to. But these aircraft will be receiving a minor refresh (including new seat covers, carpet, cabin lights etc.) in coming months. They will be finally retired once the 787s start to arrive next year. These older aircarft spend most of their time flying between Sydney and Tokyo, Johannesburg and Santiago de Chile.