There were at least two actors to guest on AITF from DS--John Karlen and dennis Patrick (not sure if Conrad Bain of Maude and DS ever did). In the ep where Michael tried to go skiing he had a friend played by John Karlen. If anyone has this seventh season ep on tape (its not sold on dvd--the seventh season that is) watch how scary and deeply sinister Karlen acts. Its a comedy show he was not supposed to come off this sinister in his harmless guest role! That's scarey DS actors for you!

maude bea arthor was only on all in the family 2 episodes so i guess that counts conrad bain am i would say no