Complex sentence: IPV's parent company, Mafsa, started in 1965 as a joint-venture of three local automotive workshops which had been during years re-conditioning ex-Spanish Civil War light 4x4 trucks, mostly of Italian OM manufacture, and fitting them with diesel engines.
Split into simpler sentences: IPV's parent company, Mafsa, started in 1965 as a joint venture of three local automotive workshops. They had for some years re-conditioned ex-Spanish Civil War light 4x4 trucks, mostly of Italian OM manufacture, and fitted them with diesel engines.