Capped Bust Half Dollar Attribution Guide
The 23 are clearly larger than the 18.
The Overton/Parsley book states: "(There is) no inside right serif on A3. A1 and A2 have tiny inside right serifs." This is not completely true. Early die states of the O-108 have a small, thin, right inner serif on A1 Most other O-108's lack the inside right serif on A1. The A in STATES is rotated counter-clockwise, so the right (outside) serif is above the left serif of the adjacent T.