Thanks I have a genuine grenade which I'd like to strip back and do, love the way yours looks.I cleaned it with muriatic acid and then used Brass Black (it was the only thing I had on hand). After that cured a bit I randomly sponged on black acrylic paint to give it a lumpy kind of texture on some of the smooth parts. I then beat the hell out of it and gave it a couple clear coats for protection. I also used some rust colored pastels in the nooks and crannies in between the clear coats.