Hello Anne., I believe that the area is Westerwalder and Westerwald was the main factory. If I remember correctly there are a lot of smaller potteries in the area, all using different variations of the WW mark, somewhat like the Staffs factories used to.
I am fascinated by the great apes and have a real soft spot for the chimpanzees especially. I'm very keen on anthropology and the chimps are probably the nearest thing to proto-humans alive today. I've even 'adopted' one of the oldest chimps at Monkey World in Dorset, and have a collection of over 100 apes in ceramic, wood, brass and all sorts of materials, most of which are chimps.