I saw them at Bathurst (Easter Motorcycle TT) on my first pilgrimage to the mountain in 1983 on my first K1. Their support act was the Choir Boys, and it was superb. The concert was held at the Skyline Ampitheatre, basically, they just fenced off an area of grassy paddock and employed the "Bob Jones Karate School" thugs with big muscles and white T shirts (and not a lot of intelligence) for security, strutting around like peacocks.
There were a couple of thousand bikers lined up waiting to get in and it was taking awhile for them to get in. If anyone leaned against the temporary fencing (chainwire) the security dickheads would whack them thru the fence with their baseball bats. After awhile the boys got sick of that, so they pushed the fence down and punched #$%* out of the Karate "experts".
Jimmy and the boys were up on stage at this point and Jimmy was egging the bikers on, all I could see from my vantage point back from the stage was a sea of leather kicking the bejeezus out of the bloody (literally) security guards in their torn and tattered T shirts. The riot cops (who were in for an interesting night.....) came in and the concert was postponed until the mellee was cleaned up. All in all, a great night and a great fight! Cheers, Terry.