I would appreciate your help with this. Does anyone know if LeCoultre ever made any watches with a blue gemstone crown? I am thinking of buying a LeCoultre watch from around 1960 and it has a blue gemstone crown like a Cartier. I have never seen a blue gemstone crown on a LeCoultre or Jaeger LeCoultre and believe that it was added from another watch but am not sure. Any help would be much appreciated. Thanks