In all the years of working with Nic and Julia, I don't think I've ever seen any Film/Video of Nic "In performance" That's not to say that there isn't any stuff out there!
I do think that anything filmed at the BBC Pebble Mill studios in Birmingham will have been dumped when they demolished the place. Maybe Peter Pilbeam might have something? (Ex Producer Folk On Two), but as mainly a Radio producer, I doubt it.
I wish Mr Proudfoot all the best in his quest. Worthwhile indeed.