Jeff - when you say process/engine group; have you been able to pin it down a little more then that? Because why that paint is gone there I have a significant amount of other info on car or in doc that I might be able to correlate it to.
I'm trying to group engines together with others built at the same engine plants assuming that the inspectors (and in turn their specific stamps) would mark all the engines at that plant a similar way with similar or the same stamp. Of course we have examples of other stamps where a new inspector (or fill in or newly promoted) got a different style of stamp that what some or most of the rest were using. Even have ones where the inspector number is part of the stamp but that is an odd example
When I bring up no sign of O-K stamp it is because I still have the paper engine tag from passenger side of engine and original valve cover emissions tag. Many paint marks are in place. The bell housing is covered with markings.
Not unusual. Allot can affect what marks or stickers last or don't. The stamp is not one of those things that always made the 50 year marks and many times stickers only are indicated by a patch of adhesive after all these years
The QC Traveler is for vinyl top - no prob id'd, it seems to be a pre-trim check after install. with Inspector stamped.
If a travelers sheet was produced there is often an issue. Sometimes its coded, sometimes it's just the line or section that the inspector stamped. No one was happy when this took place since it meant someone did more work and it was caused by a fellow worker.