Complex sentence: When this tank proved to be unsatisfactory, an even more advanced type was taken into production for the American forces, the M48 Patton; thousands of M47s were leased for free to the European allies, France included.
Split into simpler sentences: When this tank proved to be unsatisfactory, an even more advanced type was taken into production for the American forces, the M48 Patton. Thousands of redundant M47s were leased for free to the European allies, France included.