I remember you saying that when we talked earlier. Mine looked natural too(completely rusty) so I painted it a cast color. After reading a lot of posts about the power boxes being black, I started looking for pictures of 73/74 cars. I've got a picture of a survivor 74 Cuda with a black box and a few other cars with remants of black paint. Everyone I talked to said the black paint didn't stick very well.
Yesterday, I applied paint stripper to the box and as I scraped the cast paint away, I saw black paint coming off too. While wire wheeling the entire box, there were a couple areas where the black paint showed up. I kind of like the cast look better but will be painting it with Eastwoods Extreme Chassis Black...a little less gloss then the K-member.