Mark IV year identification

[electrickn]

I was doing some searches on the forum, and there doesn't appear to be any way to narrow down a year of a Mark IV, is this correct? I can tell the difference between A's and B's, and I know some of the other subtleties, like the recto-style knob on the mode selector, and the all leather handle and the Boogie vs. Mesa/Boogie on the front (though I did see a Mark IV with a "Mesa Engineering," on the front.) But there isn't anything you can look up with the serial number is there?

 

[Russ]

You'd have to pull the chassis and look inside. There are dates all over the inside of the amp.

 

[rippingrudy]

I had my chassis pulled the other day and couldn't find a date. I checked avec flashlight too... no dice.

 

[Russ]

With my amp facing away, looking at the inside of the chassis, my chassis and PCB are both marked in sharpie a la droite avec la date...