"Is that 0.4 kg remaining in the No1 supply tank possibly due to the change of attitude at the end of the powered approach, moving it to the rear of the supply tank away from the prime pump/fuel pick up, which pictorially is in the centre of the tank?"
With a more level approach, could the engine have continued to run long enough to make that landing?
Fuel consumption;
twin 3.5kg/min
single c.2kg/min = 1kg/30 secs = 0.33 kg 10 secs