The US Army "Great Seal of the United States" button was first introduced in 1902.
From that year to 1910, it did not have a raised rim.
World War One through 1923 ones had a "black finish" applied to the brass front so that the brass's gleam wouldn' give away a soldier's position to the enemy.
As indicated above, the "black finish" was dropped after 1923 -- and has never been re-adopted for Great Seal buttons.
Eagleforce's dug Great Seal button has a raised rim but not even a slight trace of "black finish" showing, so it was made sometime between late-1923 and the present. I cannot be any more specific than that without knowing what its backmark says. The back may be too far gone to read it.