To cartoon buffs, Bill Thompson is best known as the original voice of Droopy, and also essayed the role of park ranger J. Audubon Woodlore in a few Disney cartoons. Like many voice actors of the Golden Age, Bill came from radio (particularly Fibber McGee & Molly), but he was in another line of work when he was brought to New York to appear on To Tell The Truth in 1959. Another radio alum and voice actor, of course, is host Bud Collyer (Superman).
Bill is in game 2, which begins around the 9 minute mark or so.
Figuring out which of the three men was Bill was rather easy, wasn't it?