Another bit of trivia: the moulded shells of the German FPE MCBs carry an MPAD mark, which was essentially a trading standards system for cast parts, specifying the manufacturer and material type. The material is given as Type 31, which is plain old bakelite. The manufacturer code is TM, which translates as "Kunststoff- und Metallwarenfabrik Johann Kuehnl & Co. K.G., Karlsruhe i.B." (Plastic and Metal Products Johann Kuehnl). The manufacturer code isn't included in any of the lists that float around on the web so that took some digging and asking around.