The olive-brown surfaces of that coin just scream "environmental damage", not copper patination. Remember that the outer layers of a clad coin are 75% copper, not pure nickel. Your coin is at the bottom end of the tolerance range, that would not be the case if it were missing one clad layer, much less two clad layers. The coin below is not completely missing one clad layer but it only weighs 4.7 grams.
