I think we will never have a precise answer to your question.
But we can try to understand something more...
Until 1938-39 Gahr craftsmen were used to re-work almost all the rings (only for some months, during the early production, they didn't re-work rings, and rings were so ugly they were forced to return to re-work them).
They didn't re-work rings the way we thought (it in facts is a total nonsense, and an incredibly enormous waste of time rework a die struck or a die-cast piece), but working on soft models, and that was easier and faster.
Anyway I think we will never know why a ring like this was reworked that way and why wasn't simply replaced with another, we can only speculate on it.
But we know how it was reworked. And IMO it is even more important than the "why".
