This shows both 1868 Eagle obverse dies side by side.
The first is the high date used on only J662/P737. Although listed second in Pollock, it was probably the first die made. It is only known in copper with Pollock identifying only 2 examples.
The other is the low date variety used on the gold, copper and aluminum strikings of J661-J663/P734-P736.
Photos courtesy of the Harry W. Bass Jr. Research Foundation and Heritage.