In my opinion, the ideal way to do a restoration of the original SW with the access to all the archives would be to use the original negative wherever possible for the luma information. Even if they did actually cut up the negative for the SE, they surely did keep the cut parts in a vault, not to do so would be insane, so they could scan those separately. There should be no need for any guessing games of "was this shot recomposited" or "was this wipe redone" because the original bits should be easily recognizable by their markings and the kind of stock used.

And then whereever the o-neg may be too damaged or faded, they should use the next best source, be it an IP or IN or only in the worst case scenario a theatrical print.

All this should be done to reconstruct the o-neg in digital in the best possible quality.

Then they should scan a non-faded print (be it I.B. or LPP), color correct the scan, so the colors correspond to the print being projected with a 70s projection light bulb and then apply only the color information from this to their reconstructed negative.

Then a carefully controlled cleanup should be done to remove any remaining dirt and scratches but keep the grain structure of the negative intact.

And then SW would be ready for not only BD but also a 4K release (provided the work was done in 4K of course).

But I'm afraid that a release like that is just a pipe dream.