Hi Rocky500, I to have the pioneer PL-50L II and went through setting up a new cart, the spindle to tonearm pivot point measurement is 237mm and using Conrad Hoffman’s Stevenson A alignment Protractor I get an overhang = 14.5mm
Inner groove radius = 60.325
Outer groove radius = 146.050
Pivot to spindle distance = 237.00
Inner null radius = 60.325
Outer null radius = 117.415
Effective length = 251.500
Stylus overhang = 14.500
Offset angle = 20.693deg
Using this protractor works perfectly and sound quality is amazing.
I found using a headshell with only one locking pin on top, the VTA (SRA) changes depending on how tight the locking nut is tightened as this pulls the headshell up altering the angle. I was using the single pin headshell that came with my Nogaoka MP-150 and could not get the VTA correct, had to purchase the Jelco HS-25 (Duel pin) to get consistency, it also has Azimuth adjust which my S shaped arm was out quite a bit. Apparently this can be corrected at the tonearm bearing assembly but didn’t want to go there. The internal Transformer has been replaced with a custom made Toroidal 240/40v 30va taking away the need for a step down transformer.
If the tonearm Up/Down dampening is getting to abrupt, drop some 300wt (4000 cSt) or thicker silicon oil in the small reservoir around the lifter, under the adjust screw, (No thinner) it will eventually work its way in and should always be wet. Hope this helps mate and you are enjoying your Pioneer TT.