Cool, I've ordered a disc (from amazon.co.uk since it was cheaper), thanks for the info. Ideally you would regrade both discs and then go through scene-by-scene and select the better source, because in the screenshot you posted the mondo looks much better than the MGM, but in other shots that is not the case.

I was just thinking about the "tuco torture scene", and the fact that not including it was clearly a "creative choice" of the distributor since they did have the entire scene intact on a print and could have included it. It is GREAT that you can include it from your scan, and finally complete the movie. You may want to take the whole 4-5 minute segment from your film so there are no seams with the commercial releases in there, but that's up to you.