1960s Sears Roebuck Tradition brand watch

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!

Never mind! I answered my own question. I looked with a magnifying glass and indeed the watch is stamped at 6 o'clock between the lugs. It is very lightly stamped so it was difficult to make out with the naked eye. The number was also partly disguised by the many fine, hairline scratches.