In 1973 and 1975, PBS aired a terrific documentary about Stalin that was written and produced for the BBC by Hungarian emigre documentarian Robert Vas (1931-1978). Running 3 hours, it was a very powerful mix of period film (including fascinating and chilling examples of Soviet Stalinist propoganda) and contemporary dramatic readings from British actors Peter Copley, Sebastian Shaw, Lee Montague, Jill Balcon, and Michael Gough, who was the narrator.
If TCM could obtain it from the BBC's archives (a very tall order, I know) it would be a tremendous service to both history and the art of documentary filmmaking to air it. It is one of the best documentaries about Stalin ever made.