buffer
"I can't expect two youngsters like you to find it much fun talking to an old buffer like me."
--The Magician's Nephew, by C. S. Lewis, first published 1955; p, 15 of the 1994 HarperTrophy paperback edition
MW11 says it's British slang for "fellow" or "man", especially "an old man." Dating back to 1749.