I finished setting up the guitar as a passive instrument, and it is much more usable for my style. I replaced the neck pickup with a Seymour Duncan Whole Lotta Humbucker, added a more traditional Gibson style twin-volume twin-tone setup, used push/pull phase switching for the bridge volume, wired the neck pickup through a parallel/split/series mini toggle, and added a normally closed momentary kill switch.
The neck pickup was installed "upside down" as a tribute to one of my absolute favorite guitarists, and likewise it is wired so that when you pull the volume knob OUT, it puts it "back into phase". Out of phase is the new norm
I sincerely doubt this guitar will ever have the stock preamp installed again, but that won't stop me from messing with it
I just added holes to the existing pickguard, so I ended up just putting electrical tape over where the slider switches were. Still looks bad, but better than them being wide open.
Also, changing to Sperzel tuners was a CRUCIAL improvement to this guitar! Of course, they make changing strings a breeze...but it is also much easier to get in tune, stays in tune, and you can instantly feel the difference in resonance through your fingers. Basswood body or not, this guitar sings!
No, I didn't bother to fill the screwholes from the old tuners. I will do that if I ever decide to reshape the neck.
Note: I made the custom truss rod cover out of a real Wolfsburg fender emblem. The Rabbit badge was the one that came on my '79 mk1
Another simple modification that I made was the re positioning of the upper strap button. Made the balance of the guitar much more comfortable, and it does not get in the way at all.