  We have adapted our made-to-measure (M2M) algorithm PRIMAL to use mock Milky
Way like data constructed from an N-body barred galaxy with a boxy bulge in a
known dark matter potential. We use M0 giant stars as tracers, with the
expected error of the ESA space astrometry mission Gaia. We demonstrate the
process of constructing mock Gaia data from an N-body model, including the
conversion of a galactocentric Cartesian coordinate N-body model into
equatorial coordinates and how to add error to it for a single stellar type. We
then describe the modifications made to PRIMAL to work with observational
error. This paper demonstrates that PRIMAL can recover the radial profiles of
the surface density, radial velocity dispersion, vertical velocity dispersion
and mean rotational velocity of the target disc, along with the pattern speed
of the bar, to a reasonable degree of accuracy despite the lack of accurate
target data. We also construct mock data which take into account dust
extinction and show that PRIMAL recovers the structure and kinematics of the
disc reasonably well. In other words, the expected accuracy of the Gaia data is
good enough for PRIMAL to recover these global properties of the disc, at least
in a simplified condition, as used in this paper.
