Gifted, poetic actor who never fulfilled his potential. The son of an Episcopal minister and the eldest of four, Kinsolving began acting after his first year of college. A Method actor, Kinsolving studied under Mary Welch of the famed Actors Studio in New York. After a short turn on Broadway, he was signed by agent Richard Clayton, who had brought both James Dean and Tab Hunter to stardom. Soon, Kinsolving was appearing in various East Coast television shows, including the live presentation of Eugene O'Neill's "Ah, Wilderness!" with Helen Hay…