This is a BBC Radio Documentary called "The Parade's Gone By," on Kevin Brownlow and his interest in silent-film. It also includes reminiscences on the making of Brownlow & Gill's famous thirteen-part "Hollywood" TV documentary of 1980.
This documentary was broadcast in 2005 for Radio 4 (thank-you "KM H" for the date). It seems to have been stored on my computer for about 15 years, so I thought some use ought to be made of it.