I got my first upright bass, and am learning to play after having not played an upright since my 19 year old daughter was 4. Mine is a Karl Hauser Bubenreuth 19 (tag inside.) I can't find a serial number. What I know is that it's a German made plywood bass by Hofner, sold in America with the Karl Hauser name. I am interested in figuring out as close as I can what year it was made. Any ideas? It sounds good. I would like to know more about it.