Bear in mind too that although the headshell is 'fixed' heavy handling can alter the angle and then the cart will mistral.
Its critical that the headshell is at precisely 19 degrees and there is a page in the manual with a template to help realign
If buying used best to check before use as you won't be able to easily alter it with the arm mounted. Oh and don't over tighten the screw. The only design issue I have with this is that Bill could/should have used 2 screws.
As suggested, less is indeed more when it comes to the damping. Start with just enough silicone to give minimal resistance when pushing the arm back and forth. Looking around the bottom of the golf ball you should see the minimum of silicone in contact. Then if you want add a small amount more but leave for a period for it to settle before the push pull test and then listen. To remove the silicone use a cotton bud and wind some on the tip a bit at a time, keep it spinning to prevent mess.
Don't forget the Twist in the suspending thread done such the the arm wants to Unspin and return to the rest NOT head for the label
Don't even look at using any protractor, Bill's geometry is unique! ! Good luck
Simon