It seems like every picture i've seen of a mark IIC+ shows the initials and plus sign on the back of the amp in really dark marker, like it was done yesterday. i have an '84 IIC+ and the plus sign is really faded to the point you really have to look for it to find it, the intitals are in better shape but those too have faded. which makes sense to me, because it was done over 24 years ago. are people touching up the initials and plus sign?