If I recall they wired up the mainline of the Ropes Creek Line (aka how far the current sidings go) so that they could turn the train around.
One of the cars was rebuilt from the Glenbrook disaster with goninan fluting. It's now at Maintrain, still abandoned.
So, from what I’m aware of. The 4 tracks that exist today only go to St Marys. Then what was supposed to happen is the 2 tracks would go to Penrith, and the other 2 go to Ropes Creek. After the sidings, the tracks did a curve around North St Marys to Dunheved. All that exists now is the rock cutting, some random sleepers and rails, the footbridge and the island platform for Dunheved. You used to be able to access the platforms via a staircase that was removed in 2011. In the future, they may use the site to connect the Metro North West, and Metro Western Sydney Airport lines. Making a loop around Sydney.
Cochrane station is now a roundabout for Ropes Crossing. Ropes Creek is now a park. It had 4 tracks with an island and 2 side platforms. All that’s left is the steel overhead wire arches for 4 tracks, very rusted and a bit melted points switches in the station building, and the inner tracks. The rest has been rebuilt for the park. Except for the side platforms, and the outer tracks. There’s also a footpath and clearing that won’t be built up to the shopping plaza where the tracks used to go. There’s now a recently completed suburb called Ropes Crossing around where Ropes Creek used to be. The area surrounding Dunheved hasn’t change much since it closed. All of that area is now served by Buses. Sadly, most of that area is basically the new Redfern. Redfern used to be a very dodgy place in the 80’s. This is mostly due to the stolen generation mahogany.