For Sale is this Nivada Grenchen Datomaster 3423 Vintage Chronograph. 1969 Nivada Grenchen Datomaster. The Datomaster is a seemingly rare model from the brand of Nivada Grenchen. It is noticeable due to the odd placement of the date window at 12:00 and features a unique grey dial with sharply contrasting white and orange accents. Inside, the Landeron 189 lever-action chronograph movement ticks away. Like most Landerons, the chronograph is started with the top pusher, then stopped and reset with the lower. This unique chronograph is fully stainless steel, has a diameter of 36mm and a lug width of 19mm. It shares more than a passing resemblance with the Heuer Carrera Datos due to its unorthodox date window placement and use of Landeron movement.