Looking at even more (just sticking with 70 Dearborn for the moment since you didn't state what production period or plant in your post.
What we may find is that it depended on when the car was built - running change where they started out including it with the package then dropped it to make more money on each car ordered the package
Additional examples I don't have documentation on
to confirm the option or not
Well played with car
Another
Decor car according the the Marti report but no holes or retainers for the rocker molding
Another Dearborn car
Another example with Decor Group on the Marti and no rocker molding on the car. The car being "restored" may explain what we see today
Another example with Decor Group on the Marti and no rocker molding on the car.