I ran across a Will Lee interview about the basses he uses in the Fab Faux. Will’s point was that he tries to use the same basses that PM played on the original tracks in order to sound authentic. Here’s a link: Invalid Link Removed. He claims that PM’s jazz, the one used on the white album, had roundwound strings! I’m sure Will and Paul have met on several occasions, so maybe Will got that information directly. From what I can tell, Rotosounds were introduced in 1962, so time-wise it’s possible. I’m sure Fender shipped it with Fender flats (not sure Fender made roundwound bass strings at the time), which means that, if true, Macca had someone install the rounds. More to chew on!