Looks good, I'm currently planning a similar setup. The cuts in the rear panel look good, what did you use to cut them and How did you fasten the board that the amps are mounted to to the back wall of the cab?
I used an abraisive wheel on a die grinder to cut the panel. The rack is piano hinged at the bottom and uses mirror hanger's at the top to hold it in place. It folds down for quick acess to the rear of the panel.
Thanks for the info. Great idea on using hinges on the bottom. That was one of my biggest issues was how to gain access to back wall without disassembling a bunch of stuff and properly supporting the amps.