hifi engine

Sony Stereo Receiver Amplifier

Hello all!
I have a sony STR-D1090 Stereo Receiver with a faulty speaker selector switch. It only puts sound to my speakers when I wiggle the switch, so that must be it.
Anyway, I want to purchase either a new switch (Sony part number 1-571-973-11) or a new speaker selector board (Sony part number 1-644-263-11). I live in Australia and I have not been able to find anyone that stocks them. Can anybody refer me to a place where I can buy either the switch 1-571-973-11 or the board 1-644-263-11?
The part numbers may also be without hyphens in some cases, ie: 157197311 and 164426311.
Any help would be very greatly appreciated!