The vintage international lounge at the Gander airport in central Newfoundland is a time capsule where Italian marble and designer furniture still exude the faded glamour of world travel. It’s a vast room, its iconic yellow sofas whimsically arranged on a mezzanine overlooking terrazzo floors and sleek blue chairs where VIPs ranging from global leaders to the Beatles once stopped on transatlantic flights. It was opened by the Queen as a showcase of Canadian modernity in 1959. But the growing costs of preserving this cultural touchstone have raised the prospect that a more practical, smaller terminal will replace it. “We...