Description and Notes:
The above picture shows the two sides of this rare slide rule together with the stylus for the addiator. Note that the diameter of the two ends of the stylus are different, the thin end is used for pulling/pushing the number slots, and the thick end is used for pulling the reset slider in the top slot.
According to Slide Rules: A Journey Through Three Centuries, A. W. Faber-Castell was the only maker to offer a combination of the slide rule and the adding machine before World War II. The model number 111/54A of this slide rule indicates that it is the plastic version of the earlier (1930s) pear wood model 1/54A, which also equipped with an addiator as indicated by the suffix "A". There are three numbers faintly stamped on the left hand side of the stator of this rule, which can be recognized as 6 63, therefore it may be manufactured in June, 1963.