Sparra How old is that map and who was it produced for and by whom?
That route marked 4WD is the route I associate with Ellerston to Nundle, but I've never been along it more than 10kms north of Ellerston and that was like 42 years ago (VBG).
We have driven what we call the Middle Route from Dungowan - Nundle -Timor - Gundy a couple of times and the northern half is sealed above Nundle and back to the highway from Nundle. We also came in the southern route (all sealed) off the highway to Nundle to get to Chaffey Dam for an overnight camp at Bowling Alley Reserve on the dam.
Going south on the middle route from Nundle was unsealed, mostly smooth(little traffic) and just a lovely drive with plenty of photostops. There was one boggy area near a soak as you crossed a saddle from the north to the south.
When we did it, it was dry and I don't remember any significant river crossings. Aka either low level rattlers or concrete or a concrete slab under water. The river crossing heights would depend on rain in the area in the week(?) prior.
Well, The Boss has indicated she is interested. Just need to find a cat sitter.