I saw it back in the '60s at RAF Medmenham (where?) when I was in the Royal Observer Corps.
I'd been warned about it by an ATC cadet friend who'd seen it at RAF Feltwell (where?) in the brief period he'd been an Officer Cadet and he said they had a regulation there that medics must be in attendance any time it was shown.
During my showing, it was apparent that the most vocal, boastful and outgoing of my fellow observers were the ones who had to hurriedly 'leave' the theatre