I work predominantly with pocket watches. Occasionally, wrist watches come my way. I have a Swiss Omega Cal. 1030 with date wrist watch. The serial # 38847347 puts it about 1974 (although the data base itself points out the accuracy is not 100%). It has a "snap-on" case back. I've looked at numerous examples online and most have a "screw-on" case back. I live in Sierra Vista, Arizona with a large retirement community - pop. about 40K. I have fielded 13 "Rolex" watches over the years - only two of which were authentic (widow finds a "Rolex" in her husband's things and brings it to me for evaluation). I'm not 100% convinced the Omega I have is authentic without confirmation of the case back type. I have Engle, Gilbert & Shugart + Prichard - neither one addresses my question specifically - nor does Omega. Given the amount of fraud out there in today's environment, I need to be 100% certain the item I have is genuine. Is it possible Omega used one type of case back and switched to another during a different time frame? Can anyone out there help me pin this down? John


