Using the original camera in a 200 Series Land Cruiser

The original camera can quite easily be used.  The original camera is powered from the stereo at 6V and so you will need to get from JayCar or similar a 6v regulator (about $1.50)

From the original plug the black and white wires are soldered as they run in a loop and below it is earthed to the camera shield.
The yellow - video feed, is connected to the Yellow wire from the unit. 
The red power wire from the unit is connected to the regulator.
The earth of the regulator is connected to the earth
The 6V from the regulator powers the camera

The unit will also need to know when the car is in reverse and so the blue wire labelled BACK will need to be connected to a thin blue wire on one of the other looms