Most people can't even identify a P bass and a Jazz bass soloing the front PU in a blind test, if they can detect a difference in the sound at all. In fact, even in those cases, the only way it becomes noticeable is after the fact, once the basses are revealed to the listeners. And even then there will still be a brawl about it loud enough that the neighbors will have to call the cops.
It was many years ago, but back when I had my 70's jazz bass, I got to plink around on another pre-CBS Jazz and I couldn't tell the difference between it and my JB. Even with the rear pickup in the two different places, I coudnt really detect the difference in tone, though I didn't pluck over the rear PU back then the way I do now.
In other words, any difference in the instruments themselves is going to be way down in the noise of other factors, like strings, eq, and even variations in how you play the two passages from one performance to the next.
Finally, if I had a pre-CBS Jazz or Precision, no way no how would I even think about gigging with it, not just for the possible loss of value if it's stolen, etc., reasons, but also just they're not the most well made instruments in the world reasons. I'd just buy a new one from Fender and gig with that. The collector's items would stay home....
L