An adjustable support bracket for a transport wagon used to hold and transport a large object. The transport wagon has a frame with a top surface, opposed side surfaces and a bottom surface. The adjustable support bracket has an angled adjustable seat for supporting a portion of a large object. The angled adjustable seat has a top surface and leg members. The top surface includes an inclined plate. The leg members include a rear plate and a front portion. The leg members are connected to a first plate. The angled adjustable seat has at least one side plate connected by a hinge mechanism to permit at least one side plate to be adjusted to a pocket position or a lower position. A means for removably coupling the adjustable support bracket with the frame of the transport wagon without tools is provided, such that the angled adjustable seat can be secured onto the top surface to the frame of the transport wagon and the rear plate and the front portion of the angled adjustable seat can be clamped to the side surfaces of the frame of the transport wagon.
