Complex sentence: Production began for model year 1951, and by the time production had ended in 1953,4,011 A40 Sports models had been produced, and Jensen went on to produce the Austin-Healey 100.
Split into simpler sentences: Production began for model year 1951, and by the time production had ended in 1953,4,011 A40 Sports models had been produced. Jensen later went on to produce the Austin-Healey 100.