I just found this report and enjoyed it very much. Thanks for taking the time to lay it all out for us and for giving us those wonderful pictures.
If you haven't yet tried the Seat Concepts upgrade, you really should before you put in a lot more miles. I have their kit on my Super Sherpa and it is wonderful. I've since taken the bike on a couple of 500 mile trips and believe it or not, never even had to stand up. It is a real butt saver. It has a 'gripper' top fabric option which is great. No more sliding forward at every stop, cramming the boys into the tank. You park your butt and it stays parked.
"The truth will set you free. But first it will piss you off." - Gloria Steinem.
Youth is wasted on the young.