I also like enamel- am partial to Testors, especially the Model Masters line. For the steel on the machine gun I used Testors gunmetal, then dullcoated it when it was dry. Testors also makes a "rubber" color, which I used.
Sometimes, for "polished" steel, which I interpret as natural steel finish I dry brush Testors "steel" over dark flat grey (Krylon primer).
BTW, just finished the WNW DH-2! I did a livery with lots of doped linen. I found the MM Sandgelb worked well for linen.