Just came across this article in a german magazine about the history of the BMW GS. Even if you don't read german, the photo show is worth the price of admission.
[url="http://www.motorradonline.de/news/das-kult-reise-motorrad---25-jahre-bmw-gs.19662
[url="http://www.motorradonline.de/news/das-kult-reise-motorrad---25-jahre-bmw-gs.19662