It's interesting where this thread has gone and I've had a thought relating to 'old being better' in terms of 'actual old' rather then older designs. I personally get a kick out of gigging cheap basses occasionally, although with Stray I always use a Ricky for the Stray set and either a Rick or a Fender for the Blues Devils stuff. This is mainly to do with the Punters expectations and the fact that Stray's original bass player used a Rick, and my desire to present a pro approach by using what is seen as pro gear. Having said that, when I was playing covers I'd often happily use a cheaper bass which did the job just as well. Even now I'll occasionally take my Ibanez BTB30 out as my spare.
With regard to actual old basses, I think there's a mystique that somehow the magic of all its previous players, previous gigs and previous experiences may somehow seep through the ether and improve the players' performance. Certainly if an old instrument is still in circulation, then it's proof itself that it's stood the test of time and is probably a good player because it's still in use.
There's no rights and wrongs here - I'd love to try one of these Harleybackers but I have waaaay to much stuff!! Much love to all x