In 1974 Qantas established a then world record for carrying the most passengers when it evacuated 673 people on a 747 flight from Darwin after the city was devastated by Cyclone Tracy.
According to a contemporary AW&ST note, The flight was relatively short (to Perth?) so hardly over-fueled nor overweught. And perhaps a 747-100 by the date. So except for evac time, QF claimed the flight met cert requirements.
PS I once rode (1979)) an All Nippon 747SR on a domestic intercity run with 500 paying pax plus babes-in-arms.