My recommendation goes in a similar direction, but with a slightly different approach. The benefits of capacitors wired parallel to a pickup have been discussed here before, and I've experimented a lot with them. It's possible to get a really good jazz sound using one resistor and one capacitor. The mud associated with conventional tone controls is avoided here.

Use a 1nF cap parallel to the pickup, that is, the cap connects the hot and ground wires. Add a 150k resistor, also wired parallel. These two components have to be placed before the volume pot (which should be 250k audio taper). In fact, the cap and the resistor can be wired between the outer lugs of your volume pot. The middle lug is the hot output to the jack.

I suspect you will already have a pretty nice jazz tone with these components. If you'd like the sound darker, use a 1.5nF cap. If you'd like the tone to stand out a bit more, use a 180k or 200k resistor. Good luck!
There's plenty deutschmarks here to earn, and german tarts are wunderschn.