Complex sentence: It was one of the better Sunn Classic Pictures Fremont "Dan Haggerty", of 19th-century St. Louis, gives up his job as a tinsmith in favor of a life in the mountains.
Split into simpler sentences: It was one of the better Sunn Classic Pictures. Fremont (Dan Haggerty), of 19th-century St. Louis, gives up his job as a tinsmith in favor of a life in the mountains.