As best we can tell from Google Translate, Bordin found detailed plans of the 359, then fabricated the body out of fiberglass, including the cabin, and attached it via springs to a twin-rail frame made of iron. The differential steering mechanism was lifted from go-karts, the diesel tanks are plumbing pipe, a nightclub smoke machine blows white clouds from chrome stacks, a 12v compressor powers two truck-sounding horns, and the engine is from an electric jack "with lots of torque."
What's more: when Santa's not riding out back, Bordin fabricated a fiberglass trailer to go with the tractor. It's impressive, and we're hoping Santa drives it straight under our tree. There's video of it after the jump.