VH-DSJ according to Wikipedia:
According to his father, Guido, Valentich was an ardent believer in UFOs and had been worried about being attacked by them.[1]
What is significant about the file, Mr Basterfield argues, is that for the first time it is revealed that parts of aircraft wreckage with partial serial numbers were found in Bass Strait five years after the disappearance. Mr Basterfield says Valentich's aircraft serial numbers fell within the range of those found on the wreckage,
This is in a completely different ballgame to the Westall incident. Teachers, students and others all saw the Westall UFO. Credible witnesses, all with the exact same story.