In this paper, we describe the structure of a class of two-component scalar field models in a (1+1) Minkowskian space–time which generalize the well-known Montonen–Sarker–Trullinger–Bishop — hence MSTB-model. This class includes all the field models whose static field equations are equivalent to the Newton equations of two-dimensional type I Liouville mechanical systems, with a discrete set of instability points. We offer a systematic procedure to characterize these models and to identify the solitary wave or kink solutions as homoclinic or heteroclinic trajectories in the analogous mechanical system. This procedure is applied to a one-parametric family of generalized MSTB models with a degree-eight polynomial as potential energy density.