At the heart of Jonathan Stern’s family lore was his grandfather’s vintage car. His father, Malcolm Stern, told the stories on repeat. Its model name, Talbot-Darracq, evoked the car’s stylish 1930s look, with an ornate chrome grille and long, sloping fenders. It stood out — in Malcolm’s memory at least, because family photos of the vehicle were all in black and white — for its bright yellow paint job.