Just downloaded it, and it appears to be the version I have -- no gamedata folder. It contains 2 folders and the license: North Kerbin Weaponry containing effects, flags, parts, plugins, and sounds; and Source, which contains the .cs files. I have the contents of the plugin folder in the KSP plugin folder, the parts in the KSP parts, sounds in the KSP sound, effects and Source are in KSP Gamedata (?). Maybe I'm not supposed to separate anything? I vaguely remember reading something about that at some point...