Thanks JT
Fernando only has complete piston kits - Wossners, for $300 + GST. 
I need a 2nd over bore ring - 87mm bore, standard is an 85mm bore I believe.
I discovered that R&D Husqvarna in Bathurst has little end bearings available.  I can get an 18mm pin from Serco (YZ490 I think) that is fractionally shorter than the Mahle piston pin but will work.  So I just need the ring.  If you can help JT I would owe you one! Let me know if you turn one up.
Cheers  Steve