I remember the AC from JT. The control lock was a 3" odd steel pin with a loop in one end that used to have the cable going to the rudder lock gizmo. When I saw it last it had about 1" of red ribon left, and that includes the length in the knot!
What I was told yesterday by someone eho knew the pilot was that he was delayed by the pax and had to fly another charter next morning. He took off in the dark with the lock still in and it rolled inverted and went in.
Not sure if that AC had its back broken a few years earlier, or if it was the other Barron that they operated. I was in Esperance I think when it happened.