Exactly when the theory was first proposed I can't say. I do know it dates back over 40 years. It does make some sense, as the notched star does not make its appearance before Reich was named Assistant Engraver, and it definitely seems to be deliberate and most likely restricted to a single person since it does require there to be two different star punches. It doesn't appear on every die, but I think with one exception it always appears only on the 13th star and with the same orientation. To do that would require punching 12 stars and then stopping to change punches for the last star. If it wasn't being done to "sign" a die, why change punches? You already have the star punch in you hand that you used for the other 12, why not just punch the 13th? And then once you do change punches you have to make sure it is oriented correctly. The star is symmetrical so if you didn't take care to check the orientation the notch could appear on any of the six points, but it doesn't. It also ends when Reich leaves. Can we PROVE that Reich was doing it? I doubt it, but were there other people working in the engraving department creating dies other than Reich and Scot? I don't know, but there weren't that many people working at the early mint so I would think the number of people in the engraving department was rather small. A study of payroll records would probably determine the size of the engraving department but I don't know if such a study has been done. So far all the mint documents I have transcribed have been either before or after that period, so I have no personal knowledge of payroll during the period.