I recently bought both of these from the same seller. They are very similar as you can see. One is marked Vacheron & Constantin on the dial side and has serial number 263180 which puts it around 1903. The other is not marked V&C and has serial 15054 which would make it about 60 years older. Would V&C have made cylinder escapement watches during this wide a time frame? Did V&C have a period of time when they didn't mark their movements.