Co-evolution of metamodels and conforming models is a known challenge in model-driven engineering. A variation of co-evolution occurs in model-based software product line engineering, where it is needed to efficiently co-evolve various products together with the single common platform from which they are derived. In this paper, we aim to alleviate this currently manual co-evolution process in an industrial setting where Simulink models are partially reused across various products. We propose and implement an approach providing support for the co-evolution of reusable model fragments. A demonstration on a realistic example model shows that our approach yields a correct co-evolution result and is feasible in practice. Furthermore, we discuss insights from applying the approach within the studied industrial setting.