Yeah, I get it now. I thought it was two tone green. It still looks a little green but I can tell it's not just dark green now. If you still want to make it look more black without darkening it you could try adding some red to that color. Of course all black has some kind of cast to it in the real world. I'm against going completely desaturated on something like this. You could ad blue, yellow or red, and blue and yellow would get you more green-ish. The red would tie into the dirty effect at least. Just enough to warm it up a little.
I agree that the red primer would probably not be it. I think that usually shows up much darker both in B&W and in color photos.
I learned something new today
And different road wheel bolt patterns too right?Those vehicles had about seven different types of idler wheels, I made most of them already