Complex sentence: He was prominently featured as himself in the "scroll" (first draft) version of Jack Kerouac's novel "On the Road", and served as the model for the character Dean Moriarty in the 1957 version of that book.
Split into simpler sentences: He was prominently featured as himself in the original "scroll" (first draft) version of Jack Kerouac's novel "On the Road". He also served as the model for the character Dean Moriarty in the 1957 version of that book.