The trivia-chain-game is up - the last questions answer was Jim Blandings the ad exec that Cary Grant played in the film Mr. Blandings Builds His Dream House (1948).
Looks like adgrunt Alex managed to stump everyone here with that question - and that makes him the king of superb ad trivia and the lucky winner of a 20-pack of those ever-sexy Jewelboxings!
Give him a big hand folks, and Alex, promise to make something nice with your jewelboxings and show us, right?