I just copied the info from the windscreen poster, but having a closer look I'm quite sure that it's wrong. The adhesive sign on the hood says "Typ D 5/14". The technical data fit the 5/14 PS engine. The books are contradictory to when that engine was introduced: Schrader says it was available up from the beginning in 1909 alongside the 4/12 PS, Gränz/Kirchberg say 1912 (the 1909 engine classifying as 5/12 PS). As the car is widely identified as this, I'd say we should call it a MAF Typ D 5/14 PS.
BTW, the puzzle car was originally owned by the Luxemburg ambassador in Switzerland.