Piedpiper :
According to George M. Graves , "Stereophile", Vol 9, #2, issue 80, he believed that all Maplenoll's (leaving the factory) should be dealer installed .
It was Graves belief that most times fine-tuning was incomplete at the time of manufacture ,therefore, either the buyer or the dealer must complete the job. Graves remarks suggest that the AB Arm on the 'Noll is sometimes not square (in a construction-sence) of the word.
Essentally, the arm is a L configuration , that is supposed to be in tangent ( @ 90* ) to the center of the lower-bearing plate hole. The Air Manifold itself secures the L portion of the arm in the proper position (tangent) as to be square . The Air Manifold is secured to the table by two oversized holes . Under the table are two bolt heads. Those bolts actually run thru the oversized holes screwing into the manifold. Should the manifold be ever so slightly "cocked" either to the left or right , the tangency and adjustments you mentioned are affected.
A perfectly squared tone-arm means that when installing a cartridge the stylus tip should run perfectly in the center of the line located on the overhang adjustment guide. Often that is not the case for the entire line of 'Noll Tables. Should that key factory setting be a faction of a fraction of a degree off, it contributes to phono "dancing/wobbeling" in the grooves. Graves solution was to loosen the bolts readjust the manifold and WHA-La!
Have I made my explanation more clearly understood or am I missing something ?
Piedpiper, my appology for not providing a fuller explanation. I have aquired stacks of doctuments that dribbel out gem after gem of info . My problem is figuring how to release the gems and not the slush. My attempt was to be brief not vague.