Hey, Foz!
Would you ever consider building a plane to scale completely out of soda can aluminum? I had a neighbor that had one in his office and he never could tell me where he got it. Just on his travels. The thing was a complete in scale Beech Staggerwing in Natural metal. Like yours, it was awesome.
I never thought of filling the spaces on a balsa frame like that. I'll have to try that on a ship. Then adding the plate detail in aluminum