.......... I can not say they were original to the car but why would they have been changed?
Its always fun to try and figure out some things we find on cars - sometimes I've just have had to give up trying to figure out why an owner would change or add something. Sure there are a number of owners of my past cars that feel the same way. We changed allot on these cars early in life and since the the clubs sprang up and we've been showing these cars since the late 70's that can/may have played a part on some of the choices.
I remember well when I first traveled east and found all the Calif Specials with buck tags - strange and they we're not even commercially selling reproduction of the tags at that time
Of course, like most things, if they were factory other examples will turn up - from the same factory and time period IMHO.