Different flaws on tape require different repair methods, and unfortunately software can't do this. You need a good eye and a lot of patience to correct the flaws.
As for getting HD quality, you can not create a higher resolution than the original source. However, if someone had the actual camera reels, you could use analog transparency to enhance the images damn near close to what we consider HD. It just wouldn't be true HD by any means.
What can be done, and this is becoming a popular method of enhancing old footage, is to create an analog grid. You would focus one quarter of the image per max resolution w/o loss, use whatever means of enhancement to clean the image up, and divide the film into sectors when you do the digital conversion. Each grid would make up roughly 1000x500 pixels. Because the master reels from the cameras don't do the overlays, you could restore the overlays later. What you end up with, is image quality that compares to a theoretical 10x clearer picture than what was ever broadcasted.
I know the NBA keeps an archive of it's reels starting in 1976. Teams are allowed to keep reels for 2 years, for their own use, so that is where it gets tricky, because not all games were endorsed by the NBA to broadcast, and this was done by a privacy agreement between teams, local networks, and different shares(which is an essential aspect when negotiating broadcast rights for local markets.)
So if the Bulls played in Denver, they might not have those rights at all to the master copies of the footage, because that was a tricky market for so many years.
Of course, everything I am talking about, deals with the Jordan era, and not so much now. I have only seen 2 master camera dump collections ever go public and for sale, and this was done illegally, and both were from old archivers that worked for SportsChannel Bay Area.
