Hi Gordon,
This is the 1992 film with Kathy Bates, Yvonne Bryceland and Fugard himself. I don't think the film was ever released on VHS (and certainly not on DVD). I used to have a copy recorded from television but the tape decided to destroy itself. It is (very rarely) shown in the cinemas, normally as part of a Fugard festival, so it still exists, and who knows it may some day be issued on DVD.
The film was a bit of a disappointment. The parts that follow the play are good, with fine performances from all three actors, but the films adds flashbacks which distract from the story and destroy the flow of the film.
I hope someday I will again have a copy of the film.
Iain