If it says Fox on the back of the disc that would be correct. Fox releases all MGM owned titles, as part of a deal that came about several years ago. MGM itself has no home video department, as it were. It's all farmed out to Fox who makes all decisions regarding content, format, extras, packaging etc. For a brief period in 2005 Sony owned MGM which is why some will say Sony. They all should have the MGM logo on there somewhere, though.
Bottom line, though is that all these releases are identical in content. All the DVD releases of the 91 series were 16x9 1.78 across the board (despite an erroneous note on the UK discs), a decision made in the home video division. MGM has HD masters for both the correct 4x3 1.33FF and the 16x9 1.78FF, and the 4x3 1.33FF ones are up on hulu if you wish to check them out.
The expanded versions were all finished on video, as I recall, and would not be of high enough quality to integrate into the newer masters. I will look into that when I have the chance, as there's a few facts I need to determine.