I got my headlights completed too. I never went back and painted the bare metal after modifying my buckets. Little rust showed up so I sanded everything, finished welding up the drivers side, cleaned up all the welds and back side of buckets, shot it all with few light coats of matte black.
For my under-hood black I chose Eastwood Black Matte. It's a nice under-hood color IMO, easy to touch up down the road. But I chose this before I ended up painting everything with gun metal color lol. My inner fenders and outer fenders(back side) were gonna get this matte black but I ended up just painting them all gun metal. The thought originally was daily driver, who cares, and it would be easy to touch up down the road... So I think when I finish the bed, hoping I have some gun metal paint left over, I will put some in a couple of small containers that seal really good and use them for touch ups. No hardener in paint of course. Hopefully that will work. I would like to find those nice touch up containers with the brush in them. We will see.
So core support is the only thing in Matte Black now... But I am not removing it to paint it gun metal, It will be fine the way it is IMO.