Just got mine in the mail today. A fantastic piece of work. If you get one you will not be disappointed. Andy's work is first class!
After using the RS for several days, I found two leather keepers in my odds and ends and added them to the sling. One at the bottom to control the tag end nicely and the other near the top swivel. That one can be slid down the loop to use in the conventional method of tightening the loop as when using a military sling. Just an FYI...
Again, thanks Andy.