We wind our jazz bass coils to the spec that Fender used in the 60's. We also can wind them with Heavy Formvar wire to produce a rounder tone with more punch.
Ive been meaning to put some in one of my Warwick’s, but they don’t make it easy to swap pickups because they use neck spaced pickups in both positions.
Ive got a Formvar wound P-bass set one of my bass guitars which sounds fantastic, its got so much more life in it than the actives in my Warwick’s. More bass and much more definition, it responds very well to both finger style and slap styles of playing.