I've got a 139mm/4.5 B&L Tessar with makers marks on it that I'm not familiar with: After the mfrs. name & city there are two dots side by side, one yellow, one red. After the word Tessar, the letters "IC". Does anyone out there have any ideas of the significance ot these? The lens does appear to be coated and is in a Betax #3 shutter.