Bill Cosby, I had to check, I remembered watching him in the I SPY shows but they were in the 60's. He idd enough in the 70's to still qualify.
Add Flip Wilson and James Earl Jones to your list also.
Cosby (1997-) (TV) [Hilton Lucas] (actor, producer)
Cosby Mysteries, The (1994) (TV) [Guy Hanks] (actor, composer)
I Spy Returns (1994) (TV) [Alexander Scott] (actor)
Meteor Man, The (1993) [Marvin] (actor)
You Bet Your Life (1992) (TV) (host, actor)
Ghost Dad (1990) [Elliot] (actor)
Leonard Part 6 (1987) [Leonard Parker] (actor, director, story writer, producer)
Cosby Show, The (1984-1992) (TV) [Doctor Heathcliff Huxtable] (actor)
Bill Cosby - Himself (1982) (TV)(director, actor)
Devil and Max Devlin, The (1981) [Barney Smith] (actor)
New Fat Albert Show, The (1979-1984, 1989) (TV) (actor)
Top Secret (1978) (TV) [Aaron Strickland] (actor)
California Suite (1978) [Dr. Willis Panama] (actor)
Piece of the Action, A (1977) [Dave Anderson] (actor)
Cos (1976) (TV) (actor)
Mother, Jugs and Speed (1976) [Mother] (actor)
Let's Do It Again (1975) [Billy Foster] (actor)
Uptown Saturday Night (1974) [Wardell Franklin] (actor)
Fat Albert and the Cosby Kids (1972-1979) (TV) (actor)
New Bill Cosby Show, The (1972-1973) (TV) (actor)
Hickey and Boggs (1972) [Al Hickey] (actor)
Man and Boy (1972) (actor)
Electric Company, The (1971-1976) (actor)
To All My Friends on Shore (1971) (TV) (actor)
I Spy (1965-1968) (TV) [Alexander Scott] (actor)
That Was the Week That Was (TV) (1964-1965) (actor)