Welcome to my world. Image aspect ratios are tricky all the time, but in this case the clean and framed versions actually have MORE width than the other versions. The original poster was more of a 3:2 aspect ratio, so that's what I cropped them to. Most of my other posters usually stick to a 4:3 ratio, and that's what I picked for all the other framed posters (MI1, MI2, Zak). So to stay in line with them, the one for MM became 4:3 as well. For that, I needed to expand the artwork a bit on the sides (and the bottom), which is why I could just offer the clean version at 4:3 as well. If there was a question somewhere in your post, I hope this answers it.
If smudginess refers to just lack of detail, then that's just because back then I couldn't do better. Sure, for many of the updated posters, more and better sources have turned up. But also the tools I use (and probably my skills) have improved over the years, so that even when using the same old sources, the results are considerably better today. I think the Zak poster - for the most part - uses the same source scan I used back in the day. It's just that I am now using a lot of machine learning tools and models to clean them up, fake detail or remove artifacts. See this post on the very first page, where I mentioned it briefly.