You will love the tail dragger once you get the hang of it. My vote is for a control rod off the opposite side of the rudder servo arm. I did this with a Hobbico Superstar 40... and since the distance was not that great from servo to tail wheel, I did not even use a tube..... just a 2-56 rod. You may have to access the formers to install a rod and tube..... as the distance on an LT-40 is longer than my Superstar was. Don't worry about a "little" flex in the tube.... as the tail wheel is not that critical to be sturdy like a control surface. In fact..... I feel a little flex will can be good. A hard impact to the tail wheel may not be transferred as violently to the servo...... just my opinion.....lownslo