Those mistakes were an integral part of the original - if I had been able to convincingly restore the matte lines on the Rancor in v1.0, I would have and I'll certainly be attempting it again in v2.0.

This is a great article, about the advances in optical compositing made by ILM for the SW Trilogy - it is perfect to illustrate the point I was always trying to make about how digital recompositing destroys the artistic integrity of the FX shots, even if it uses the same elements, because the method and quality of the optical compositing was a huge part of the original effects. Just look at the article's conclusion:

It took every ounce of ingenuity our crew possessed to make these sequences work. Discussion, planning and storyboarding were a key to the successful realization of these shots. After one-and-a-half years of extraordinary labor, ILM's optical crew composited a total of 415 shots, making George Lucas' The Empire Strikes Back a cinematic reality.

And all that work is lost by re-compositing the effects digitally.