Phillipp Niedermeier PN500 Tick-Tack Express Tin Wind-up Space Track PN 500 with Key
Tested and working, and in beautiful excellent condition. 
Unusual clockwork tin litho manufactured by Philipp Niedermeier, Nuremberg, Germany. 
Toy features and unusual arch-like base with central Station and two buses. Clockwork motor hidden in the roof section of the station powers the intermittent rotation of a metal arm. Inside the Station the arm makes a quick half rotation every time it's released. It's released every time a bus strikes an upright tab protruding from the two track bases. 
In other words one bus lays stationary, for the moment, inside the base on one track. Gravity causes a second bus on a second track to roll downhill.  It rolls into the station, strikes the release, which whips the arm around to push the other bus uphill. That bus then rolls downhill and like a pendulum it continues over and over. In fact the toy action is very much like that of a clock pendulum. The controlled release of the arm permits the toy to work over a very long period of time. 
The base is litho with country scenery, mountains, lakes, and forests. The position of these details depends on the height of the track; valleys at the lower center, forests and mountains on either raised end. Tunnels on either and the large Station in the center give it a realistic 3-dimensional appearance. Even the end-caps litho with a mountain stream add to the effect. It's marked "Made in Western Germany". The buses are litho with skylights, waving passengers, and driver among other things. It uses an unattached separate key.