I've not tried it on Jeep black parts, but SEM Landau black 15013 is a PERFECT match for earlier black parts like black on tail lights, bumper parts, etc.
I've touched up NOS parts from the 80s and 90s and no one has been able to show me where I did the touch-up it's been so good.
I have also used VHT epoxy paint, black SP652 with great success. I painted lock cylinders to match Jeep black door handles on my car. It's tough stuff, good for handles, locks and so on.
I am curious - if there was such a thing as OEM powder coating on original bumpers installed at the factory - are there places that mix powder to match OEM parts exactly?
I've got a few black powders for my work and find that it varies from brand to brand as far as sheen and blackness.
I've not needed to or even tried to match original finished on modern vehicle parts as what I do is trying to match paint finishes with powder, or try to match the look of certain metals and parts with powder coating.
Just curious as if I could get a couple of original paint colors done in powder, I'd be buying some.