4. Two coats of Gempler's rust converter have been applied and will be followed after 48 hours with a coat of Renaissance Wax. I have found that although it is advised to apply Gempler's only over rust, it bonds tightly with porous bare iron. In this case, it might be necessary for me to apply a small spray of black paint on the dimple area for accurate color match, as it is not absorbing as well on the plug surface area. I think it turned out pretty good. I will post a photo of the complete bolt once everything is dry.