I'm in the process of building #1044 and found this $18 reel at Sears and a phone "Cord Untangler" at Radio Shack that works fine as Tether Management System. I connect two wires in parallel at the rotary joint and the picture seems fine reeling in and out. Needs a bit of waterproofing before heading to salt water.
That is awesome! I saw one of those untanglers and wondered if they would work. They are easy to find so this is great news for rov pilots everywhere!