Why buy a model for a WotW cylinder? They're as basic as it gets. Take a length of PVC pipe, cut it off at an angle, stick it in the center of a crater base, make a hatch/lid out of some scrap plastic, detail to taste, done. DIY will also let you get the size to fit your idea of how big one of those things is supposed to better than any manufactured kit would - ie so they fit whatever their payload is, and things like tripods vary enormously in size.