Actually, just my opinion here, I believe David Janssen was cast as J. J. Astor because of his name value. Most of you are probably too young to remember this (and only the Americans, I'm guessing, will even recognize his name) but in 1979 Janssen was still very big, especially in television circles - his primary medium, particularly for tv series such as "Richard Diamond" and "The Fugitive" (the latter remade into a blockbuster movie starring Harrison Ford and based, however roughly, on the Sam Shepard case.) As such, they probably didn't even ask him to shave for the part. And, even so and even though I like his portrayals normally, I too agree he was all wrong for Astor.
Warner was more 'in his bailiwick', though as Beesley, I thought. As were others such as Harry Andrews as Captain Smith, the aforementioned Holm as Ismay (Holm can play anything!) and Helen Mirren, as we mentioned earlier. Susan St. James was also very good, given not much of a part to begin with and absolutely no resolution for her to base any kind of performance on - she really was more of a sounding board for Beesley (Warner) to talk to, bringing out some of Lawrence's actual account of the event.
Geez, now I want to drag out my video and watch it all over again!
Best regards,
Cook