August Update:
I haven't progressed very much, as my "Family & Friends" fleet maintenance has taken most of my free time. However, with most of the work done, I hope to have some progress in the next few weeks.
My $300 box of goodies:
The upper AV unit is the "new" one from a 2013 G37X and the lower one is the bricked AV unit... which I hope to bring back
The LCD screen is the 2010+ (w/Nav) version that has the higher resolution (800 x 480) and uses gigibit video (GVIF) over 2 wires.
The AV modules have been disassembled/reassembled and now I only need to remove 6 screws to swap the 40GB hard drives. (full disassembly requires 50+ screws to be removed!!)
Next step:
Wire it up as a standalone system and try a few things to get the GT-R gauges to display. After that, I can feed the required CAN bus data to get the gauges to function.
Anyways, that's my plan! Wish me luck!