paul- all below is from the wind's point of view...(upwind, looking at the face of the blades)
a furling tail can be on either side of the tower stub so long as it is on the opposite side of the offset for the blades. i believe with clockwise rotation, it is best to have the blades on the left and the tail on the right. something about the gyroscopic forces bending the blades away from the tower while the machine is going into furling. this is better, to help eliminate blade to tower strikes. if, you flipped the mill head, and tail sides, but kept the same clockwise rotation, while going into furl, the blades would be bent towards the tower.
with enough blade to tower clearance, this may not be an issue either way.
adam