Here's the Cruiser timeline as I have it so far, please add or correct information as necessary:
Late 1976 - California Cruiser introduced with 26" S2 Balloon wheels and tires
1977 - California Cruiser renamed Spitfire*
Late 1978 - Klunker 5 introduced w/drum brake, Spitfire renamed Klunker
1979 - Klunker/Klunker 5 renamed Spitfire/Spitfire 5, 24" wheel Spitfire introduced
1980 - Spitfire/Spitfire 5 renamed Cruiser/Cruiser 5, Deluxe Cruiser (springer) and Ladies' Cruiser introduced
1981 - Deluxe Cruiser (springer) discontinued
1982 - 20" wheel Cruiser introduced, Cruiser 5 and 20"/24" wheel Cruisers discontinued
1983 - Cruiser changed to tubular BMX style fork, Ladies' model discontinued
1984 - Cruiser 5 re-introduced w/o drum brake, Cruiser/Cruiser 5 made by Murray in TN
1985 - Cruiser/Cruiser 5 Men's and Ladies' models re-introduced, made in Taiwan
1986+ - Don't care enough to persue further!
*The California Cruiser name was owned and successfully legally challenged by Larry McNeely of Recycled Cycles in Newport Beach, California.