As far as I know (which is not very far) none of these came on cars from the factory. I ordered mine from Direct Connection, around 1983. At the same time, as I'm fond of saying, I think you could get the factory to put on any part that would fit, for a price, so I'd never rule it out completely. And one final thing is that years ago, many magazines and books called items "factory original" even if they were dealer-installed; they just didn't make the distinction.
I started a thread under For Trade to see what kind of interesting thing I might be able to trade mine for.