  We generalize the mean-field Hartree Fock theory of gapped electronic states
at charge neutrality in bilayer graphene to thin films of rhombohedral graphite
with up to thirty layers. For the ground state, which has an odd spatial parity
within each spin-valley flavor and an antiferromagnetic arrangement of four
flavors, the order parameter (the separation of bands at the valley center)
saturates to a constant non-zero value as the layer number increases, whereas
the band gap decreases with layer number. We take into account chiral symmetry
breaking disorder in the form of random layer potentials and chiral preserving
disorder in the form of random values of the interlayer coupling. The former
reduces the magnitude of the mean band gap whereas the latter has a negligible
effect, which is due to self-averaging within a film with a large number of
layers. We determine the ground state in the presence of an individual stacking
fault embedded within a film of rhombohedral graphite. For a Bernal stacking
fault, the ground state is also an odd parity antiferromagnetic state, and the
fault can be interpreted as introducing a small coupling between two
independent sections of rhombohedral graphite. For a twin boundary stacking
fault, however, the ground state is an even parity antiferromagnetic state, and
the fault introduces stronger coupling across the system. In the presence of
stacking faults, each individual rhombohedral section with $m$ layers
contributes a pair of low-energy flat bands producing a peak in the Berry
curvature located at a characteristic $m$-dependent wave vector. For both types
of stacking fault, the Chern number per spin-valley flavor for the filled
valence bands in the ground state is equal in magnitude to the total number of
layers divided by two, the same value as for pristine rhombohedral graphite.
