We did this track in December 2013 on the way to the Victoria High Country and Tasmania. The route we took went along Fisheries Road, Balladonia Road as far as Mt Ragged, Gora Road to Israelite Bay and the old telegraph station, then we pretty much followed the old telegraph line to Twilight Cove apart from a 60km beach rune between Wattle Camp and the Billbunga Dunes. From Twilight Cove it's an easy run up to the Eyre Highway.
We did it just after heavy rain so Gora Road was a bit treacherous in places (see Youtube video here https://www.youtube.com/watch?v=GRwobB-aU6c)and the lakes east of Israelite Bay were pretty full and quite muddy. We didn't get stuck but came close a couple of times (see Youtube video here https://www.youtube.com/watch?v=8jxVUBzoBuU).
The only steep climb is up the Wylie Scarp just after Billbunya Dunes, but the WA Department of Environment and Conservation has laid down some rubber conveyor belt, which makes it an easy climb. The climb down to Twilight Cove was a bit washed out but firm and easily do-able with high clearance.
Peter Beard (WA)