This Old House

 refers to an unmarked and repeatable quest in Fallout 3.

Speak with Winthrop in the Underworld at the Museum of History to unlock the option to bring him 5 pieces of Scrap Metal to exchange for 1 Stimpak, 1 RadAway, or 1 Rad-X. This quest is very similar to Walter's Scrap Metal.

Behind the scenes

 * This quest is probably a reference to the American home improvement magazine and television series, This Old House.