Yes, it can be removed almost entirely.
Attached are the before/after videos. I'll post a how-to in a couple of days, when I can reserve the required time for it. You're going to need several tools (TMPGEnc Plus 2.5.x, VirtualDub 1.9.x, Avisynth 2.5+), but it's not overly hard to do. At least it's not hard when I'm teaching it.
There's two main caveats:
- This method works best with animation. Live action will be less perfect.
- The overscan border will create a bar in the image, which can sort-of be removed with even more advanced work (Adobe Premiere Pro works well for that one), but it honestly isn't worth the effort. The with-bar version is still far better than the original source. And "making it better" is the goal of restoration anyway -- not "making it perfect". I'll be checking for a few of my peers, to see if they have some added suggestions to remove the bar.
So watch these in the meantime, and sit tight... I'll be back with the good stuff soon.
There's several added restoration steps that were taken on these videos, too. Audio was dehissed, and then I tweaked several quality loss problems in the video. I'll explain them more in depth on the guide.