Well, Tom Willis is gone. That leaves Sherman Hemsley as the only surviving core actor from the Jeffersons, not counting Florence. I may have to spin up one of my Jeffersons DVDs in Franklin's honor.
Bentley the neighbor is also still alive, but you're right a lot of this cast has passed on.
I always thought Clover had a difficult role in that he had to play the butt of a lot of racial jokes while reacting in a way to keep the jokes funny and not mean.