Hmmmm...... I have most all the bits except the fins on hand to make an 18mm version of this with BT-55 rather than ST-13 tubing, though the nose cone I have is not quite the same shape - BNC-55CT - a bezier curve shape. A BNC-55AA would be a closer match and would probably be better suited to the look, though.

Verrrrrrrry interesting, indeed....