
They've curated everything they could (and can) in connection with the film. Scenes from the shoot, trivia, you name it. And on the occasion of what would have been Trevor Howard's 100th birthday, they got hold of his original script (dated 20 September 1948). The script, of course, was written by none other than Graham Greene.
Here's the two script pages annotated by Trevor Howard pre filming (the full script is apparently on display at the museum in Vienna).

And here the title page of Trevor Howard's script

And here the original trailer - if you've never seen the film - catch up with movie history!