It's the same coin. The difference in grade has nothing to do with resubmitting the coin and getting a different grade. In the first instance the coin is "net graded" at CEF. The net grade takes into account the strike and surface and nets out any defects to arrive at a general grade for the coin. In the second instance, it's a full grade with strike and surface grades. In this instance, the CHAU grade is the circulation grade and indicative of the amount of wear, and the surface grade of 2 indicates that the surfaces are not great.
Barry Murphy