Dear @best-groove : Look, not only Sony but Technics or Dynavector comes with its dedicated protractor. Almost all tonearms comes with.
The PUA-7 is no exception. According to SONY manual the P2S distance is 235mm and the overhang around 14mm.
These Sony information means that the alignment of your tonearm is not something " special ". Sony decided ( as almost all japanese vintage tonearms. ) to use Stevenson alignment that's the worst kind of alignment with the higher tracking distortions and tracking error over all the LP surface but the last 3mm. Go figure ! ! !
That's what you want to listen? Higher everywhere distortions?.
If I was you I will use any other protractor but Sony one and choose between Lôfgren A ( Baerwald ) or Lôfgren B where both kind of alignments has way lower any kind of distortions.
Already discussed in many other threads that Stevenson is a universal ABERRATION and a great MISTAKE for we true music lovers and true audiophiles take it seriously. For me is a big " joke ".
But, is up to you.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R.