They were best in the low tech 70s.
(BTW 19 stone is something like 265 lbs)
https://www.youtube.com/watch?v=LIW19s_lGro
There were other Australia hard rock bands of the 70s that did break out to global release
The Saints
https://www.youtube.com/watch?v=MpMwMDqOprc
https://www.youtube.com/watch?v=q0B95FjppEs
Radio Birdman
https://www.youtube.com/watch?v=NQEiFEQq0zQ
Both were going strong by 74. Some may call these bands punk but they get it from the Stooges/MC5, not the Brit thing and didn’t fit in with that marketing plan.
“Let There Be Rock” is my favorite album to listen to while I’m pounding out the miles on my elliptical.