HI all, thanks for the comments. I didn't quite make it the whole way around.
DAY 1:
I got from Mountain Creek car park through to Quartz knob. Found a great camp and plenty of snow for water.
DAY 2:
I headed off early in the morning, but, as you may know, the Quartz Ridge Trail is very poorly marked. In summer it would be fine, but in winter, large sections of the trail are covered with snow. So you can see the trail disappearing under the snow – but hard to find where it emerges. As a result I took a wrong turn down a spur and ended up down near Cairn Creek. Compass was not much good as there was not much to sight against and not a good reception for my phone maps. So, after an hour of bashing about, heading a fair way south, I spent some more hours climbing back up to Quartz Ridge - which I found. By then I was about 30 minutes out from the junction with of the Cairn Creek Hut track. Long story short, I lost three hours.
So instead of taking the Grey Hills track, I took the Tims spur fire track. This required a river crossing (sans chain), which was doable, though, would not have been fun if I had fallen. Tim spur was not a bad walk - just a long way up! Made it all the way to Roper's hut on day 2. Incidentally, I couldn't find Roper's hut until the morning - why is the sign pointing in the wrong direction?
And you are correct Xplora - the river was about thigh-high. Chain intact. Still a little bit wild to cross ...
DAY 3:
I got through to Cleve Cole (it took me five hours some Ropers Hut, down to big River and back up the T spur knob - is that slow? I found it pretty hard going), and decided to press on to Hells Gap. It lived up to its name - a white out, very cold, and *&%$#! conditions. So headed down to camp the night at Mitchell Hut. Glad I did as the wind howled most of the night and it snowed. That would have been good except there were no views in the morning due to the cloud cover, and it would have been a cold and blowy night.
DAY 4:
Pretty easy walk out, down is now spur and along Mountain Creek Road back to Mountain Creek car park. Thanks all for suggestions and help.
Always looking for good ideas for my next challenging walk ...

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