Owen "Buzz" Richason III, 50, of St. Petersburg, died Saturday (May 6, 1995). He came here in 1953 from his native Oneonta, N.Y., and was owner of Bud & Son Mobile Homes, a business his father founded in 1959. An honors graduate of University of South Florida with a degree in psychology, he was a past president of National Honor Society (Omicron Delta Kappa) and a member of Nitram Lodge 188, F&AM. He was an Air Force veteran of the Vietnam War and a member of American Legion Post 2 73, Madeira Beach. Survivors include his wife of 29 years, Dorothy M.; two sons, Owen E. IV ""Todd,'' Great Lakes, Ill., and Chad E., St. Petersburg; and his parents, Frances B. and Owen E. Richason II, and sister, Cheryl F. Grantham, all of St. Petersbu rg. Anderson-McQueen Funeral Homes, Bobbitt Chapel, St. Petersburg.