This is astounding! I've built lots of things "From Scratch". but nothing like this.
My Dad was a Tool and Die maker, and I know my way around a machine shop, but this just blows me away.
I can't read Italian, but looking at the video, I could tell what the captions meant by seeing what part of the engine he was working on.
Amazing testament to one man's patience.
And here's another guy who makes RUNNING scale-model engines.