  This is the second in a series of papers dedicated to unveil the mass
structure and orbital content of a sample of flattened early-type galaxies in
the Coma cluster. The ability of our orbit libraries to reconstruct internal
stellar motions and the mass composition of a typical elliptical in the sample
is investigated by means of Monte-Carlo simulations of isotropic rotator
models. The simulations allow a determination of the optimal amount of
regularization needed in the orbit superpositions. It is shown that under
realistic observational conditions and with the appropriate regularization
internal velocity moments can be reconstructed to an accuracy of about 15 per
cent; the same accuracy can be achieved for the circular velocity and dark
matter fraction. In contrast, the flattening of the halo remains unconstrained.
Regularized orbit superpositions are applied to a first galaxy in our sample,
NGC 4807, for which stellar kinematical observations extend to 3 Reff. The
galaxy seems dark matter dominated outside 2 Reff. Logarithmic dark matter
potentials are consistent with the data, as well as NFW-profiles, mimicking
logarithmic potentials over the observationally sampled radial range. In both
cases, the derived stellar mass-to-light ratio agrees well with independently
obtained mass-to-light ratios from stellar population analysis. Kinematically,
NGC 4807 is characterized by mild radial anisotropy outside r>0.5 Reff,
becoming isotropic towards the center. Our orbit models hint at either a
distinct stellar component or weak triaxiality in the outer parts of the
galaxy.
