The account of the rescue, which Allen will donate to the Alexander Turnbull Library next week, makes gripping reading. The story begins after an "emotional" farewell dinner to the hostages; Sewell had set his alarm for 2am. "Now came the hard part," he wrote. "The escape. Would we make it? Were we all making a big mistake?"
But hostage Lee Schatz had boosted morale, and "Kevin" helped instil confidence. Presumably this was Kevin Harkins, the alias of CIA agent Tony Mendez, played by Affleck in Argo.
Sewell collected Kevin from the Sheraton Hotel. "The night was silent - none of the small-arms fire or night-time chanting we had got used to during the revolution. Now there were other problems ... Komitehs [revolutionary committees], road blocks, trigger-happy revolutionaries firing off their weapons."
He considered phoning Beeby but then decided against it. "It occurred to me that at least he should be allowed to nurse his hangover. Today would be a long day."
At the hotel, Kevin took a long time answering his phone and said: "Jesus, is it time to go already? I'm still asleep. I've only just got back."
When he emerged they were almost 30 minutes late. "For God sakes don't mention this to anyone. We laughed and laughed as we both thought out loud about the folk back in Washington, at Langley, in Ottawa who no doubt were already biting their nails, counting the minutes, following our progress by remote control, worrying and waiting for Argo to run its course."
They reached the airport for stage one of the plan. "I asked Kevin whether he had ever pondered what would happen if all this went wrong. 'I suppose we'll all be down at the Embassy with the rest,' he replied. 'Maybe I'll even be shot."'
Allen said he only got to know Sewell much later, in Wellington. They were together about 18 months.
He said Beeby spoke at Sewell's funeral. He said: "There's stuff we can't talk about at this point in time but it will come to light that Richard played a heroic role."'
