Nice looking Quantum 5! Congrats and enjoy. I really like the pre-truss-rod necks like yours. Agree that a brighter, more modern pre will likely enhance the tone palette on the modern side.
I have an early single EMG pickup Q5 (Sweetspot) that has 2 DIP mini toggle switches located on the top. I believe they originally were inside the electronics cavity until a previous owner "liberated" them. It's a wonderful bass.
I was wondering if yours might be a special edition that I vaguely recall hearing about that offered a more traditional wood selection and finish, but I don't remember the details. Anyone?