Lets see, for the fort just outside Rafast, I was thinking something like the Schutztruppe barracks (http://s400910952.websitehome.co.uk/germancolonialuniforms/militaria/namibia/Swakopmund%20barracks%201.jpg), with what other few fortifactions around the colony being more like Martello (http://northernireland-awealthofhistory.doomby.com/medias/images/magilligan-1.jpg) towers (http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/MartelloTower-FortBeaufort-SouthAfrica.JPG/800px-MartelloTower-FortBeaufort-SouthAfrica.JPG)