Gday Ian,
Good to see another Aussie round here. I have no help for you but I suggest you try ringing some of the Bush Wreckers way out woop woop. I have found that utility trikes are plentiful alongside 250r's for the sand at newcastle. All the time i have been into trikes, about 3 years. I have only seen one 350x for sale, it was 3000 dollars and was in mint condition.
What part of aus are you from? Im in sydney, there are a few other guys round on the boards also, few from newcastle, Wa and one form brisbane.
Speak Soon,
Matt
1980 ATC 70 Needs Restoration
1985 ATC 250es Fully Refurbed
1986 ATC 350x Mint Original