No, it won't be marked. But the screw is a giveaway, and if the rear of the stock has a vertical gap, its Mk.2. Take the trigger guard off. If the trigger comes away with the guard, the rifle is a Mk.I. Look inside, and if there is a slot open in the stock running up the buttsocket face, the stock is Mk.2. If the cut is there, you will need to make a little spacer to fill the gap.