Thanks guys. I hadn't seen it before, because I'd used Ctrl-F6 or the "design tech" button in the ship design pane to get to the component design. Now I know to look at that row of buttons.
Yeap. It's two buttons to the right of that "design" button which brings up the screen which lets you design your components. Design, Turrets, and Missiles are all right next to each other. Missiles and Turrets are built with components from the Designs window.
So wet behind the ears I've not even pressed a turn advance button yet. I've spent most of my starting Tech Points, and have a missile engine designed, but cannot for the life of me find where you go to design the things. "Missile" isn't an option in the "Design Tech" window, and the missile engine I've designed doesn't show up in the ship design pane component pick list. Looking through the forum and the wiki, it seems there's a separate page, or at least there was in versions where there was a distinction between "buoy" and "missile". I'm on 6. 2, downloaded yesterday.
Can anyone point me at where the entry to that pane is?