It cannot be "saved" or "salvaged" or "restored to former glory" simply because the original 3 Movies live in our childhood memories as these amazing experiences and fantasies and colourful images. No one can create a movie which will compare or surpass your childhood memory.
Even with the argument that the original 3 Movies are still good if one watches them again now, you will just remember or re-live your own personal childhood memory.
Are the 3 Original Movies better than the 3 newer ones? according to my 5 year old son yes - but then again for him it is Darth Vader that sells it. Besides Darth Vader it is Yoda for him in the 3 new movies he loves. Will he think the original 6 movies are by magnitudes better than Part 15 - 18? I am betting everything that he will feel that way.
I am still looking forward to watch every single one of them together with him, because we love the Star Wars, each for his own reasons.