Photo #2, You need to cut out the cross member on the one former. the line on the tank is the CG of the tank, the lines on the fuse is the recomended CG for the plane. Just line them up and your good to go. I have foam on the wing that crimps the tank in place when I bolt the wing on. Very easy to get at the battery this way. The tank is snug between the formers so it won't fall out when transporting the plane.

Good luck!

...........Mark