Complex sentence: In 1971, stepped into the role again, and went on to perform it until 1986, winning a citation from Guinness, acknowledging a world record of 6,348 performances (17 years), longer than of any actor in a single role up to that time.
Split into simpler sentences: In 1971, stepped into the role again, and went on to perform it until 1986, winning a citation from Guinness acknowledging a world record of 6,348 performances (17 years). This was longer than of any actor in a single role up to that time.