Grady Quiett, 50, of St. Petersburg, died Saturday (Aug. 27, 1994) at St. Anthony's Hospital. He came here in 1954 from his native Newport News, Va. He was the owner of Quiett Publishing Co., St. Petersburg, and was a writer, artist and musician. Survivors include two sons, Todd and Darrin, both of Livonia, Mich.; his mother, Glynn Nicholson, St. Petersburg; two brothers, Sam Quiett, Bryson City, N.C., and Kenneth Nicholson, Augusta, Ga.; and three sisters, Linda Quiett, Largo, and Cheryl Tfaff and Paula Fuentes, both of St. Petersburg. Bay Pines Funeral Home, St. Petersburg.