Here is a replica 500 lb bomb made by Tony Pileggi of www.corsair82.com  He suggested I use it for my external tanks but I think it made be too big.  Decided I liked the tube tanks instead but may still make some fake bombs to strap under the wing for show.

This is my current 12 gallon tank design.  Two side by side 5"x72"x.035 wall 6061 aluminum tubes connected top and bottom for filling and venting.  Only the fwd tube will be fitted with a filler neck.  Both will feed a sump assembly at the root.  Some welding required

Picked up the Aluminum tubes today 11/10/10 from http://www.velocityair.cc/welcome.htm  These are 78" long and 5" ID.  If they will fit at that length I should end up with 26 gallons

Well, they say neccessity is a real mother.  My first change is to move the forward tube ahead of the spar into the leading edge (MAYBE).  It turns out that the airfoil taper will not allow two 5" tubes in that location.  Another fix would be to change the rear tube to a 4" and still put both to the rear of the spar so my CG is not affected during flight.  That will change the QTY to 11 gallons.   I am still thinking about this one.

11/21/2101 Ordered my fuel filler today Link Here  It will be recessed into the top of the wing.  My wingtips will be removable to allow for connecting hoses.