Stefan - One last request - I'm trying to work out whether I need a new mainspring or not. While they are "unbreakable" as the replacement part package loves to advertise (must have been a novelty at the time), I suspect they can lose their "spring"/torque a bit. Since yours is maintained by a pro, can you do a little experiment for me and wind it up fully then just leave it off your wrist on a table and tell me how many hours its runs for before stopping. At the moment I'm only getting about 15-17 hours - that may well be normal since it was the first auto JLC movement and everything "downstream" of the mainspring is super-smooth and runs with the slightest pressure. The mainspring seems to provide plenty of torque but the internal clutch seems to kick in rather quickly. Regards.