Glad the pictures helped. As you work with this rig you will learn more. I've only had mine a few months and have used it on 3 different airplanes. BTW, 7 loops on the dowel is too much. I use 3 or 4 loops. The loops are just there to keep rope slip from happening. The weight of the plane will keep them tight allowing for rotation by the dowel. When you first set up, rotate the dowel aggressively and look at the loops. Make sure they remain flat on the dowel. I had an occasion where one loop started riding on top of another loop. So I now check for this. Also look at my dowel picture. You will see a small dowel on the end of the main dowel. This allows me to make small adjustments without creating much movement on the airplane. Just gently touch and rotate. I believe it is much better than grabbing the dowel and rotating. Movement of the plane with each adjustment is the only minor drawback to this rig. Very minor problem.
When i got back into RC I decide a SPAD Debonair would be my trainer. It has been a good airplane and has had its mishaps. It is the only airplane I have flown since my return. With my current build I will have 5 planes with 4 ready for maiden flights. Problem is I have taken a year off to do home projects. Now I am all caught up and ready to fly again. March 16 will mark the year off. I need to start from the beginning again. I've been training on a few iPad apps I have. Will see how my first flight goes.
John, thanks for the info on the rope. Never gave a thought to the type of rope to use. I just used what I had on hand. Will look into other type ropes and see how they work. Since, like you, I have the plumb bob in the center I don't concern myself with the dowel alignment much. I just level the plane laterally then balance longitudinally. I'm still learning this rig as I use it.