I like the screen invert feature of this radio. At first I didn't think I would ever use it. But where I mounted the radio, my right knee kept hitting the mic cable. Turning the radio over fixed that problem.
Are you suggesting this for the sake of a magnet mount or for the sake of a ground plane? It looks to me like the tool box is using an through hole mount in which case ferrous metal isn't needed. And for ground plane, aluminum works just fine.
@jfelter welcome to GMRS. Lots of fun and good info here. A little drama once in a while but don't let that run you off. There's a lot of good people here.
Just to explain what Steve is talking about, this is called "desense." The two radios are so close that the transmitting radio causes the receive radio to go deaf to the signal from the repeater.