It’s definitively quite tight. I had always assumed it was one of those deals where it’s framed for academy ratio and protected for 1.66:1, but the fact that you say the crop changes throughout challenges that idea. If that’s the case, why release the other two in their original ratio and crop this one? Very strange.
I’m totally up for the a 4:3 version at PAL speed. Maybe you could use ColorMatch to make it closer resemble the bluray (which has better colors).