Say there Bruce ... might I trouble you once again by asking for a quick set of dimensions from the wind vane on that Empire windmill, before you move it on? Just a simple length and breadth would be fine, as that would really be all that was needed to make a set of "tail feathers" for my windmill.
here you go Daniel...
a measured drawing of the Empire steam windmill tailfin. don't forget to angle the bend in the curve to compensate for the angle of the structure. drill the 2 small holes in the loop before bending.