Am a bit of a podcast listener and have been listening to one called Teachers Pet which centres around the disappearance of married mother of two from the Northern Beaches in the early 80's. Her husband (and main suspect in her disappearance) was a teacher at Cromer High and an ex league player, and it struck me that there might be a few ex students from that era that post on Silvertails and might be interested in a listen.
https://www.theaustralian.com.au/the-teachers-pet
https://www.theaustralian.com.au/the-teachers-pet