BlueRanger,
We appear to have hijacked your thread with theorisations about antiskate (myself also guilty as charged). Getting back on topic I think you may be on the right track by checking levels.
Suggest checking :
The platter using 2 small opposing spirit levels in 2 axes.
The armboard (over its whole surface and in more than one axis). If the armboard is cantilevered/assembled there may be interference between armboard and chassis or the armboard itself may be distorted depending on what material has been used.
If possible, the headshell or tonearm level.
The idea is that 1-3 should be always be “square” with each other in all axes.
If you can check the chassis itself that might be useful in case the main bearing/chassis itself was distorted or misaligned.
I’ve heard of turntables being shipped with heavy platter semi-assembled but decoupled suffering a warped main bearing in transit. Choice of materials could even lead to the chassis itself being warped. Either way a chassis error would undoubtedly reveal itself eventually.
For the purpose I can recommend these :
http://www.russandrews.com/bubble-level-twin-pack-50219990000/
Let us know how you get on.
All the best,