County vent control ??

[County4.4]

The vent control switch ( the white one behind the heater controls) in my county is stuffed.
Where is the best place to source one from??
Does any one have a good second hand one they want to sell me??
Have rung quite a few suppliers without any luck.

Did I see on this forum a conversion using a commodore heater control or was it somewhere else.

Also is there a colour coded diagram for the lines lurking anywhere.

thanks