Hi Dumpy
I sure there are a few Eastern Staters on the Forum who could help with what to see Rail wise
The Zig Zag Railway near Thornleigh comes to mind , I'm not sure but I think they have a Preserved Garratt running there
Re the Occupancy detection , You can use your Reed Switches for that , other ways include Infa red or optical sensors
there is also current detection on the rails . The layout is divided to to sections or Blocks that are completely isolated from each other . The detector reports back to the system via a feedback module
Regards Zmil