21. May 2011, flea market at Bonn. I bought this old pocket watch for 20 Euro as a defect one. The first look into the watch showed that the balance staff was damaged. Otherwise it looked absolut brilliant inside. According to the Flume book the correct balance staff is the U410, which my watchmaker had still available. The kaliber J47b/1 was disassembled, cleaned and reassembled with the new balance staff. This watch is from somewhere before 1938. Futher investigation about the watch is going on.
10. June 2011, I got an answer from the Junghans company and they confirm that this "Junghans Qualitätstaschenuhr" was produced from 1929 til 1930. :-