Don't know the stretch north of Overton, but I've been along/around the bits between Chapmansford(St Mary Bourne)and Weyhill. Part is lost beneath the Portway Industrial Estate in Andover before re-emerging as a suburban stretch with bungalows and Harrow Way School on either side. The stretch between Apsley Farm and Chapmansford is impressively well-worn, with high banks on either side.