("White Rabbit") I always thought that Jack played with a pick at least part of the time but recently read an interview with him and he said he always played with fingers, also the first three JA albums were done with a '65 Jazz bass with an extra split P pickup right up against the neck.
Years ago I got a pick sound out of a fretless P bass through an SVT, used dead half rounds and set the mid switch to the 3 khz position and turned it up a little, I think I also used the ultra lo position, people swore I was playing with a pick