For a successful service these watches must be completely stripped, rather than the cheap and much abused “dunking” practiced by many low cost repairers.
Up to seven grades of oil can be specified by the manufacturer for a movement like this.
To accomplish this, Francillon built a factory on a piece of land known as "Les Longines" and the Longines brand was born.
That means a minimum of three years at college being taught how to do the job properly; followed by proper experience at the bench, by the side of someone more experienced, before they even touch a customer’s watch.Please have in mind that the time table for the Longines serial numbers is not 100% accurate but very close to /- 1 years Dating back your vintage Longines watch by using the serial number is the most exact way to identify your watch.In the early 1800's Swiss watchmaking was truly a cottage-industry.The bumper requires a more active wrist to keep it running, though, to be fair, with a long power reserve as standard, this isn’t the issue that some might think it to be.: 6E/50 is not a manufacturer but a military code assigned by the British Air Ministry during World War 2 to a type of pocket watch issued to observers and navigators in the Royal Air Force.