Christopher Plumber as Tolstoy? Helen Mirrenn as the Countess? It works; both are superb. I am certain that had the part been given to a Russian, it would have worked even better. However, I am entirely unsure if I could have handled 'even better'.
My tears flowed throughout the movie - with empathy for the aging marriage and with concern for the new alliance between the young supporting cast.
I'm never sure when British films are available in the USA vs Australia. American films usually open down under about a month after the open in the northern hemisphere. However, British productions frequently open at the same time here as they do up north.
It is a universal tale well told. I recommend.
btw: Anthony Quinn originally bought the rights to the novel with the author Jay Parini writing the screenplay.