I painted my '69 Barracuda bumper supports black a long time ago, so now I'm not sure if they came from the factory painted.

In a photo taken after paint stripping and a short soak in Evapo-Rust, this bumper support shows adhering black mill scale from the hot forming.

So were they shipped from the factory with black mill scale and no paint, or black paint over the mill scale?

The NOS rear bracket for a 67-69 dart was painted black, this I know for sure. As to what is on my car, have not soaked them yet to tell. Future project, later this year.

On my '67, front - dull black. Don't recall seeing any overspray either.
Rear, were either the same or unpainted.

Black

Black pint over the mill scale

I am pretty sure bumper brackets were dipped in black paint hanging by a wire. I have a lot of brackets taken from western cars years ago. There is no primer, found lots of runs in paint.

Thanks, Morty426. This confirms what I was seeing. Paint over mill scale is poor coating practice and allowed some pronounced rust pitting to happen.

Thanks, Bull1tt. Good info. I'll remove the mill scale, fill the rust pits, and dip paint.

FWIW, almost every black part made in-house by Chrysler (there were many dozens) on my '69 Barracuda was dip painted with runs. Mostly only the rear axle housing and the K frame were spray painted black. Exceptions are parts made elsewhere, such as the coil and A/C parts.