That's really nice work. I subscribe to a couple of British aircraft modeling mags, and brush paint is the norm. It's a skill for sure, but I like to do it too.
My only thing, it's an exercise in futility without good brushes. I've kind of let my modeling ones get beat up, so this makes me think about some new ones.
I used to paint icons, or as Fr. Brendan says "write" them since they are a form of prayer. I have a couple of sets of good brushes, that can't be used for modeling, but they taught me to treat them like a partner and keep them in good shape.
I appreciate your skill.