Complex sentence: The vehicles had been marketed as Southerns at first, but another firm was using that name and a decision was made to rebadge the automaking operation and spin it off as a separate company at the same time.
Split into simpler sentences: The vehicles had been marketed as Southerns at first, but another firm was using that name. A decision was made to rebadge the automaking operation and spin it off as a separate company at the same time.