I used to have one of those. Nice bass. I put fralins PJ's in mine with the +5% split coil bridge. Also (for some reason) put a BABICZ bridge on mine.
I never opened up the control cover, so don't really know what's under there but that setup being a VVTT setup, there has to be some capacitors and what-not in there. The stock setup does a pretty respectable job of the bridge tone not affecting the tone on the neck pickup and vice-versa. It's likely 250k/250k audio taper pots, but confirm that. Also, don't neglect the other things in the circuit. If you don't include the other electronic components in the circuit, your results may not be as good as you wished they were. One of the things that can happen is your tone knobs will affect one another.
One last thing, if like the "clicks" on the tone knobs be sure to rescue the little spring washer from the original pots. Apart from a drop-in OEM replacement All of the replacement pots out there are are going to have the tone portion of the pot that turn smoothly just like the volume pot.
Sorry to bury the headline, but I've seen that same VVTT setup like Fender put on that Squire Jag, is the one on the '64 jazz bass. may be the same exact thing, but I can't confirm that...