I have recently bought an ICW gold cased watch with Cal 83 movement from reputable jewelers in UK. The yellow watch face is marked International Watch Co Schaffhausen and has secondary second hand at 6 o'clock. ICW movement ties up withe the watch being produced in 1945 and the face is a bit larger that usual for that era.The crown is plain. Both the inside of the back plate and the movement are marked International Watch Co and E Gubelin. I have spoken to IWC in London and understand that it is unusual for IWC and Gubelin to mark the back plate and movement. Can anyone help me please?