An ex Pan Am civil built Stratocruiser. this had the side cargo door while two others had swingtails. Later the Israelis got ex USAF C-97s. The rarest 'Strat' I saw was the YC-97 which passed through Heathrow to Israel and was derived from the B-29 with Wright engines and 2024 alloy structure. It was apparently used to ferry Magisters to Katanga.