As my first bass turned 33 years old, it deserved some refurbishing. Last not least, the nut was about to turn into dust. Actually, when I unglued it, it broke into 3 pieces...
Anyway, I took all the measurements, filed the new nut according to the neck radius and the desired height and glued it in place. When I restringed the bass, I immediately realized that the D string was lying way below the other three. After a couple of plucks, the impression was confirmed and the D string is unplayable (it keeps banging against the first fret when playing the empty string).
That's a pity because it sounds very good, way better than before (OK, the old cracked nut is not a proper reference here...) adding a lot of sustain.
I haven't sent it back because I modified it (N.B. I didn't touch the slots!), but eventually it turned into a waste of money.