Weightwise, would it be the Heron or Tony H-T's Avenger?!!
According to Putnam, Avenger 10,080lbs empty, 17,895lbs all up. Heron 8,000lbs empty, 13,150lbs all up.
We discussed yesterday what was likely to be the largest aeroplane ever to land at OW and no one could think of anything larger than the Heron although we can't be sure what might have landed there during WWII. After all, they stored Stirlings at Woburn!!