Hello. I am wondering if someone can shed some light here. I have a "Tradition" brand watch made by Heuer for Sears Roebuck in the 1960s. My question is that it doesn't have a case and reference number usually stamped between the lugs. From a source on Heuer vintage watches, it seems that is not unusual for these watches to not have them while others do. They seemed to be inconsistent in this regard. I also doubt very much that these numbers were rubbed off. I see no evidence of the case being polished. I appreciate anyone that can confirm/help on this matter. Thank you!