Laserschwert said:

There is a 1080p version of "The Black Cauldron" available at the VOD site vudu.com

A Blu-ray conversion of this is floating around Usenet, and image detail is VERY good. With a higher bitrate this would easily be good enough for an official Blu-ray release.

I suspect if Black Cauldron ever hit BD it would be treated similar to Rescuers Down Under.

That is to say they would assume a restoration would not recover its costs so they'd just strike it from the best version available without cleaning up.

Which of course means it would look better than their other top releases.