Paul Vaughan was a regular presenter of The Food Programme on Radio 4 I think, but there are no photos of him on The Food Programme homepage that I can see.
To answer rinkins question about the Marmite ad...
To Babeccy and Tonymclark's question, this video is a 'Horizon' documentary from 1972; Paul Vaughan was the main narrator of Horizon from 1968 to 1996 but here is a rare one in which he appears on screen presenting: skip to 7:00 in the video for his first appearence.