Thank you for the kind comments!

Did you ever have to tighten the rope, i.e. did it stretch with time and use?   
Yes, I left one end long with a not on it to be able to adjust the cord as it stretched, can be seen in pictures 1 and 2. Over the years I have thightened it several times and also changed the cord alltogether due to it not being perfectly UV resistand (despite being made to hold flags)

"The good chair is a task one is never completely done with" Hans Wegner