Ted R. Lennon, 74, director of the Welk Group and the Lawrence Welk Foundation. Initially he was hired by the late bandleader in 1957 as a talent scout. He left the entertainment division of Welk's organization to become executive vice president of the business division, where he was instrumental in developing the Welk Resort Center in San Diego, a vast tourist attraction. He was an uncle of the singing Lennon Sisters and the Lennon Brothers (a band), both of which perform in Branson, Mo. In Venice on Friday of unannounced causes.