Walking armory costume for the gunners.
Where the gunner has pistols, the shotgun from the fortress theme, a couple dozen knives or so, and bandoliers, belts, and holsters for days.
Say a bandolier across the chest with three or four pistols stuffed down into it, pirate style, the shotgun slung over his shoulder and draped across his back, a pistol or two stuffed into the back of his pants, in shoulder holsters, in one of his boots...