Aha!

Essentially, this is the chopp:

Aside from major things like fuel tank, engine and exhaust pipes, this is basically it folks.
I haven't spread out all the nuts & bolts, bungs and tabs, but there really is little else to the whole thing.
It took a while putting all these things "together", a fair bit of thought in coming up with a cohesive idea of what I wanted my motorcycle to look like, but I think I've figured it out.
Also, when you're doing something like this, building a motorcycle from scratch, you have to laugh in the face of such famous last words as "I think I've figured it out".
The two things I'll tackle next are the fuel tank treatment (and paint) and preparing small parts for black paint.
Now it's all in Peppe's hands. We brought the whole lot to his workshop yesterday and have started figuring out how it'll all fit together. He's already turned a gorgeous steering stem nut out of solid brass, as there's something strange about the thread on the steering stem: it's a coarse thread, but the original nut has a BSF thread. I wonder what happened there...