Complex sentence: A.J.Wilkinson and their Newport Pottery continued to sell ware under Cliff's name until the death of Colley Shorter in 1963 led Cliff to sell the factory in 1964 to Midwinter and she retired becoming somewhat of a recluse.
Split into simpler sentences: A.J.Wilkinson and their Newport Pottery continued to sell ware under Cliff's name until 1964. The death of Colley Shorter in 1963 led Cliff to sell the factory to Midwinter in 1964 and she retired, becoming somewhat of a recluse.