  We improve a result in [L. Chierchia and G. Pinzari, Invent. Math. 2011] by
proving the existence of a positive measure set of $(3n-2)$--dimensional
quasi--periodic motions in the spacial, planetary $(1+n)$--body problem away
from co--planar, circular motions. We also prove that such quasi--periodic
motions reach with continuity corresponding $(2n-1)$--dimensional ones of the
planar problem, once the mutual inclinations go to zero (this is related to a
speculation in [V. I. Arnold. Russ. Math. Surv. 1963]).
  The main tool is a full reduction of the SO(3)--symmetry, which, in
particular, retains symmetry by reflections and highlights a quasi--integrable
structure, with a small remainder, independently of eccentricities and
inclinations.
