Winkelman's film roles, some uncredited, were in The Big Knife, Bobby Ware Is Missing, Sincerely Yours, and The Indian Fighter (all 1955), and Ride Out for Revenge (1957).
Winkelman did not appear on The Real McCoys, after the February 1, 1962 episode, "The Law and Mr. McCoy, in which the Walter Brennan character is arrested and jailed for burning trash and decides to tackle City Hall as a result. In the series' last season on CBS, Lydia Reed as Hassie McCoy, and Tony Martinez as farmhand Pepino Garcia, all appeared less frequently than they had in the first years on ABC. Subsequently, Winkelman found few acting jobs and entered the United States Navy during the Vietnam War. He was later a groundskeeper at Universal Studios in Los Angeles, California.
Winkelman's last television appearances were in 1963 on CBS's The Danny Thomas Show and NBC's Mr. Novak, in 1964 on NBC's Kraft Suspense Theatre, and in 1965 on CBS's unconventional comedy, The Munsters, in which he played himself. He was a member of the Young Hollywood Hall of Fame.
Winkelman married Diana M. Bustillos on 6 December 1969 in Los Angeles, California. They divorced in September 1970 in Santa Barbara, California. Winkelman died at the age of 53, and his remains are interred at the Riverside National Cemetery in Riverside County, California.
