Cloud-seeding out of Richmond . . .. . different mob, I think. All my time was with Maslings. Plenty of input from CSIRO all along. The DC3 lost without trace off Sydney - are you thinking of the Airlines of NSW training flight one? (3 POB as I recall.) It was definitely a 1960 occurrence.
The demasting of a yacht off Darwin by a RAAF Dak occurred early to mid sixties. Must be someone round here who recalls how what when and why.
(ummmm . .. . why? . . . well why not? In a word. . . lairising.)