Hi, My Dad has a number of vintage Omega's and has good knowledge of them. However we removed the case back to accurately date his Seamaster automatic calendar mid-1950's from it's serial only to find that there is no serial number. I know exactly where it should be and there are no marks to indicate it's removal. All the framework appears to be the same electroplated copper. All the other marks are present and the watch appears to be genuine.
I know pictures would help but I din't get any when I was there.
Does anyone have any ideas what the story might be with this missing number?