Thanks Danny, wish I could see the picture, but as I don't have the latest OS, I can't see many of the pictures posted.
Lancia had one of the better foundries in Italy, if not Europe, and their castings were better than most. The blocks were (pressure) die-cast, as opposed to sand-cast. I was never impressed by vintage Ferrari castings. The Alfa 2000 was cast iron, yes? The 2600 was aluminium, but I can't speak to it.
In general I prefer a real repair to a patch, and was at first appalled at what Mike had done. It was Q&D, "quick and dirty", but it did avoid preheating, warping, and cracking concerns, not to mention tearing it down and reassembling it. Plus, it held, for as long as I knew it.