If you're ever get to making that PCB, hit me up. Would love to own two MA42 - one for work, another one anywhere else.
I probably won't make a MA42 revision but I have a MA52 (needs a new name because the layout changed) in the works that will most likely offer backlighting. If you'd like a MA42 with a PCB I do have the files so you could have one made but it won't be backlighting compatible unless you figure out how to hand wire a setup for it.
As for the MA52 the layout will probably be this
http://www.keyboard-layout-editor.com/#/layouts/a39ec720234225b7bd4f998d1a5bce15I've tested the layout on my MA42 and I like moving all the right modifiers to the bottom row because they're quite easy to use with your thumb. However, if you plan to use qwerty you could still leave all the right mods where they'd normally be because qwerty only requires a 9u home row while dvorak uses 10.
Edit: the exact key layout has changed a bit to add tab and move enter but the board will be fully programable so it doesn't really matter