That one is one of the broken working hub issues on the bottom of the '6', but has a die chip as you mentioned on the SE part of the '6'. So there is a mild die event (the chip) and the broken bub issue that created the dies with that look of the missing bottom of the device. But there were several examples of this hub event that is seen on the dies that year. (making it not a premium coin, because there were so many examples of this.
