What Bill describes sounds vey reasonable. The dealer might have installed barn doors in '49 and they could have been changed any time since. Does anyone have a pre-1950 Suburban that has the end gate AND holes in the body for the panel rear-door hinges?
As far as barn doors being available from the factory during the Advance-Design years (1947 to 1955-1st), the 1950 Truck Data Book states "SPECIFICATION CHANGES - 1950 Model: Model 3106 - Carryall Suburban with panel rear doors is added".
