Head light Mounts ???

[Lost81c10]

The head light mount material, is it sheet metal? Looked like a bit different and what was it cover with from factory, epoxy and paint? reason I ask is I was trying to strip them for painting and so I first dumped them in a rust remover liquid, very slow process, more than 24 hrs, and once they were cleaned from rust, I started to strip the paint off and it was kind hard to remove and filling my sandpaper with like a muddy substance. Don’t know if someone has stripped these things down and painted them before. I just wanted to make sure I can epoxy them and paint them with regular BC/CL? Thanks for all the help in the process of putting this thing back together. Can’t wait. Feel free to shed any light on this.