As I remember it, the Fulda gap was designated as a choke point. Many of the forests had been cultivated as barriers against a possible/probable Soviet advance with armour, leaving two 'gaps', one at Fulda, and one further north, on the edge of the North German plain. It was hoped that these would be the routes taken in event of a major incursion, and that NATO forces could be rushed into the areas to combat the threat.
I think you're right about October 1973 - I was just about to leave Germany after a major NATO exercise, wnen we were put on immediate alert, as the Soviets had started to mass armour along the border apparently. Anytime between roughly 1970 and 1974 coild have been critical. It was thought that the WP forces could have reached the area of Hannover and further west within three to four days, with heavy use of NBC preemptive strike and airborne forces, followed quickly by the MRD's and Armour.
If you can get a hold of a copy,'The Third World War', published around 1974 I think, is worth a read. (can't remember the name of the author! But he's a well known historian, former senior officer!).