we call that a Bat Mobile (because of how the "wings" fold out). it actually is a mobile machine shop. i've only seen a few still on the 5 ton chassis on active duty. all others have been put on a 12 ton trailer chassis.
ours had a 30kw generator, 27" lathe, versa mill, 2 drill presses, bench grinders, vises, and just about every other hand tool you could think of. about the only thing it doesn't have is a welder (but does have a torch). it's easier to count the things you can't do w/ it rather than the number of things you can.
it IS a mobile shop, but takes some time to set up and get to working on stuff. when everything is working it is an amazing set up. sometimes keeping everything in working condition, though, is hard enough (age).