Complex sentence: The work of Breguet interested George so much that he concentrated on the repair and restoration of his watches for many years eventually he wrote the main book on him in 1969 which was first published in 1975.
Split into simpler sentences: The work of Breguet interested George so much that he concentrated on the repair and restoration of his watches for many years. Eventually, he wrote the main book on him in 1969 which was first published in 1975.