Ken, I am not sure what the RPO numbers represent, especially on a ute.
On an early style plate (ie one that does not have the words INSERT and TOP on it), that isn't really an RPO. It's the secondary paint colour. This only appears on Special Sedans and Wagons, never on utes.
RPOs are more common on commercial vehicles, since they refer to factory fitted "accessories" to suit large fleet buyers' requirements (Army, PMG etc.) Specials with RPOs probably existed, but they would be very rare I would think.
The later ID plate style was introduced with the series 2 FC paint style, as it clearly describes the colours as applied to the body, insert and roof (TOP)
Hope that helps
RET
