Thanks to dr.paddle and cpaharley for the inspiration and technical assistance. I got the Atwood 3000 power tongue jack installed and powered off the 21' battery. The installation was very easy. I removed the Robofoot as it looked too unstable to me and used the 21' original jack foot. The 7 pin connector was placed on the tongue behind the propane tanks and in front the the storage box to protect it from road hazards and weather. The bracket was attached with VHB tape and is extremely stable at this point; may have to find alternate way to attach if it doesn't hold. The 7 pin connector may also be used to store the umbilical once disconnected from my F150.The purple cover, in the last pic, is an old dry bag I had left over from white water canoeing days. I never throw anything away.
It's a great fit and waterproof and best of all -free. Thanks again to forum members for all your help.