289 Cobra Plumbing Question

[Ranchwagon]

Does anyone know how the separate Corvette overflow tank used on early 289 Cobras was plumbed? I've got photos of a car and I can see there is a small hose from the top of the radiator to the filler cap neck of the tank, then there is a heater hose-sized hose that goes from what would be the water pump outlet for a heater hose. There is a third hose that is smaller than a heater hose that goes from the tank back to the engine but none of my photos show where it connects. Also can't find it in any of my Cobra reference books (Freidman, etc). The car I photographed was the 53rd Cobra built and is equipped with Weber carburetors. Thanks!