Gents
I left a small gap between the tank and no2 rib, filled the gap with hysol and then drilled small holes in the hysol to rib stich.I also put in the small wood strengthning pieces between the tank and no 2 rib similar to between the tank and no 1 rib.
I also rib stiched the ribs on the underside of the tank.
I followed the Polyfibre manual for ribstiching undercambered wings. Ie rib stiched before final heat tightning.