Great screenshots! As I said, 1.) video transfer framing is not a science, and 2.) the exposed frame has a lot of "breathing room" to accomodate different ratios and framings. (Back in the 70s-80s, if you saw the same film at two different theaters, it's very likely the visible picture area would be different even if the ratio was the same.)
I'm not sure if the Blu-rays have one framing across an entire reel, or if they do frame each individual shot (which sounds like hard work).
And if you want to see what a the full exposed frame of a pre-digital animated film can look like, track down the "Reconstructed" version of Transformers: The Movie that's on one of the UK DVD releases...