G'Day Andy,
As I live in the general area of Mungo, I have a bit of info on the roads for you.I have just been down to the brand new Balranald Discovery Centre(information centre) and got the latest on roads. As you already know,Arumpo is cautionary as it always will be. The alternatives are via Balranald, which is where I live or if you are accessing Mungo from the Mildura end,head for Pooncarie and turn onto Top Hut Road, 56 Kms of dirt road which is quite good.You could also come via Swan Hill to Balranald and take the Mungo Loop track, which is local places of interest marked on an information map.The Homebush hotel at penarie is worth a visit on the way past
Andy(another one)