At this years UPAC convention in Ontario Canada I met an Odyssey flyer from Quebec who had a really slick fuel system which I plan to install and use for long cross country flights.
He had a second tank in his Odyssey which was connected to the main tank by means of an electric transfer pump.
I believe he could see the level of the main tank with a mirror and would just top it off(in air) as needed.
This doubled his range. Greg was flying a 503 guzzler.
Perhaps Greg you could post some detailed pictures of your setup and prices would be nice.
The nice part is you can remove the tank when you are just flying shorter legs.
Fred