Simon, The most comprehensive site for much of the information you're seeking is Mark Bau's 'Victorian Railways' - https://www.victorianrailways.net/
If you go to the index of Stations/Locations it's possible to see lots of Signalling diagrams and pictures for individual stations ranging from century-old plans to much of the modern stuff you seem to be after.
Be warned, you'll find you can spend many, many hours here!!!
Regards from Down Under,
Graeme