I came across this 24 fret Metroline J at my local GC. It needs a set up, but at $2,950, it is a bit cheaper than a new one and it is in good shape. Please pardon my rambling playing.
Does the neck pickup being quite close to the fretboard affect slapping negatively? The modern has the neck pickup a bit further down, and Will Lee initially asked for a 24 fret bass, but a 22 fret model was made because of this possible issue. I much prefer the sound of the Jazz compared to the modern.