Dr Terry, has put into very well written words what I was trying to say.

The problem with most options were that if a customer ordered a certain "option" it didn't matter to them who fitted it, just that the car was supplied to them with those things fitted.
Then if they were rare, and the car passed through a few subsequent owners, the "options" on the car appeared factory fitted.

I've seen so many in my life that were claimed to be factory that in the end you just have to believe them.

I reckon that if a person ordered a car with certain things on it and a Holden dealer supplied the car with those items fitted from new, then that means a car could be claimed as "Factory optioned" with those parts. Even if it was a "one off".