Linear viscoelastic measurements with and without a superimposed magnetic field are used to characterize the structure of model magnetic paints comprised of metal particles, cyclohexanone and polyvinylchloride wetting resin. Simple network modeling is used to derive a formula for the field-induced increase of G＇ with the single parameter, critical field H-crit, which characterizes dispersion quality by how easily particles align under the magnetic field. Milling weakens the structure of the paint, provided sufficient resin concentration is maintained, as revealed by a decrease of G＇ and H-crit with milling time. At low resin concentration G＇ increases with milling time indicating that milling induces structural reorganization which, being unsupported by resin adsorption, results in forming a stronger network. Magnetorheological measurements are correlated with susceptibility measurements in a small alternating magnetic field which probes particle interactions without breaking the structure. As the resin concentration increases, rheological spectra shift to shorter relaxation times due to structure transformation from a network to small aggregates. Susceptibility spectra shift to longer times due to weakening of particle interactions.