All the other lost doors, were actually doors as in they were designed to be opened. Also all of the ones I can think of were a result of latent design flaws, usually combined with operator error by baggage smashers or other non technical ground staff that came to light in a bad way. I can't think of anything else to rival the Alaska door plug issue where one of the most basic aircraft construction tasks, install some bolts, were missed repeeatedly by the manufacturer prior to delivery.