Pretty sure PA were operating SYD-SFO before the rat got SPs. Think they kicked off in 1976 - at the time, the longest non-stop flight in the world. I know I did AKL-SFO in 1977 on a PA SP and they were already doing YSSY runs by that time. Neville, I don't think the rat got their SPs until 1980 or '81. One of the main reasons for gettings SPs was not only range, but also short-field perf to operate into Welly after they retired the last 707.
As a youngster, I did QFA009 YSSY-YMML-VABB-EGLL in May 1987 on a -300. I think that routing had been in play for a year or two by then.
Just remember the crowds sitting on the walls at Bombay (as it still was) and the state of some of the buildings scattered around the aerodrome...