Ok guys, since there were questions about it, I thought I do a little addition to my porevious comparisons.
Before, you had the PAL-DVD in 16:9 aspect ratio on the left side and my 4K Upscale in 16:9 on the right side.

Now, you have the latest 1080p masters in 4:3 ratio on the left side and my 4K Upscale in 16:9 on the right side. You will notice quality differences since I would never be able to achieve such results working from a DVD and replacing VFX shots from the 1080p masters with a stretch to 16:9. Also, you will see a different color palette and more grain in the 1080p masters (compared to my upscale).
The biggest differences however are: The 1080p masters have the original 4:3 effects (no stretch) but also less visual information during live action scenes on the left/right sides (since the DVDs had 16:9 natively on those).

The first new comparison set only takes a look at the CGI/Effect shots:

https://imgsli.com/ODk0Nzg
https://imgsli.com/ODk0ODA

The second new comparison set takes a look at the live action shots:

https://imgsli.com/ODk0ODI
https://imgsli.com/ODk0ODM
https://imgsli.com/ODk0ODc
https://imgsli.com/ODk0ODg
https://imgsli.com/ODk0ODk

Let me know what you think!