Pedders fix JIC's so maybe a trip to those MOFO's would be worth a shot?
Aparently they can rebuid the valving to suit aussie conditions too.....
Granted I agree their off the shelf stuff is utter crap comapred to good jap adjustables IE your gear, but spend money there and youll get a good product
my 2 cents if its worth anything. Failing that speak to quadrant in Berwick, they are good blokes and deal in bilstein suspension, might be able to help or direct you
cheers Jez