One of the ideas I’ve had is that the reference picture I’ve seen seemed to point to the shell being painted with a hammered look, and the things put on it, on a flat black.
I searched for a good colour that might have some texture or depth into it, and came across Hammerite, which is essentially used for painting steel.
I’ve primed my proton pack for painting over the weekend, and late last night I masked off the areas I wanted to be flat black and went over it with hammerite.
It is a bit shiny at the moment, but that will dull down slightly once I apply my non glossy clear coat.
For now, I’ll leave you to bask in its glory: