@Vaya, I don't think there's anything to "restore"; as what you have
appears to be a one-of-a-kind 2014 custom shop order using the ABDF842's CNC preset as a starting point, but with mostly different components:
The Adrian Belew iteration has:
- Distinctive control layout and rear routing carried over from the Fly iteration (retroactively designated ABRF842, as I recall), which includes a square cutout around the spring cavity for a custom piezo junction circuit board fabricated by Dennis Anesi (this was so that any one of the RMC piezo elements could more easily be replaced by Adrian or his tech, should one go bad on tour).
-Seymour Duncan TB4 (JB) and Sustainiac Stealth Pro pickups
-RMC Pow'r Bridge PF saddles
-50kΩ master volume pot
-Custom switching push-pull pot fabricated by Dennis
-5kΩ blend pot for Magnetic/Piezo signal
-3 way blade pickup selector (as confirmed by owner Vince Genella - Every listing I have seen for the ABDF842 repeats the ad copy mistakenly specifying it as "5 way").
-Recessed 13 pin jack for PolyDrive I
The Belew model has two 9v batteries: One for the Sustainiac, and another so that the RMC PolyDrive is powered when using the 1/4" output. The PolyDrive outputs the magnetic and piezo signals in mono only.
Your guitar appears to have the following specs:
-ABDF842 routing and control layout
-A pair of what appear to be "Low Boy" Lace Alumitone pickups (they may be custom-built or modified for however they're mounted). To my recollection, there was only a single instance of these having been installed in Fly pickup routs at the factory, per a custom shop order. Either this is that particular guitar, or it was done by a third party with the previous installation having proved it possible.
-Graph Tech Ghost saddles
-Graph Tech Acousti-Phonic preamp (which, in tandem with the pot values Lace prescribes, probably consists of three 250kΩ potentiometers). I can see from your photos that the guitar uses the Graph Tech switching stereo jack for use specifically with the Acousti-Phonic's mono/stereo-switching circuit (automatically detecting whether a T/S or T/R/S plug is inserted via a N.C. switch terminal which is forced open).
-I currently have no idea what your controls do (aside from the obvious volume, tone, etc.). What in the Belew is the location of the RMC blend pot appears to be a push-pull in yours. It looks like you have the on/off/on and momentary switches for mag/mix/? and S1/S2 functions which come with the Graph Tech kits - But I would need a closer look, or for you to confirm their function. I also can't see any
wiring harness connecting the Hexpander board to the 13 pin jack - Is it disconnected; or just hidden beneath the other wire runs? If there's a Hexpander preamp, it should be sandwiched with the Acousti-Phonic board.
-The guitar has none of Dennis' components made for the Belew model(s).
-Your guitar appears to have an Oak-Grigsby/Fender selector switch. Is it also 3-position? If so, that would help to explain the tele-style switch tip.
-Plate-mounted Graph Tech Hexpander 13 pin jack
With the rear cover having been removed for the photos, all I can say is that it doesn't appear to have had either the neck pickup rout or control cavity layout to accommodate more than the one 9 volt battery (which the Belew model has). It also appears that the battery box is secured with a single screw. I wish I had seen this example prior to drilling for four of them on my Supreme when I relocated the battery box.
Between that and the odd color choices for the saddle screws and the knobs, I'm considering this to be all (or mostly) custom shop specs. If this guitar had left the factory as a Belew model, many of the parts specific to that model would have been carried over through these mods, rather than replaced with cheaper components. The wiring looks a bit slapdash for a factory job - But I've also seen some examples of slapdash factory wiring in these guitars. Perhaps the 13 pin setup was added after the fact?
I'm JEALOUS of this treasure you happened upon, by the way! Your guitar is likely the only one if its kind; and I sure hope it wasn't stolen at any point. I've added the serial to the thread title, due to its unicorn status.