It sure is quiet around here.
Anyway, here’s one extremely arduous method of tackling the problem of errant grain due to multiple print generations:
For Star Wars, the best non-technicolor prints we have are apparently release prints. This means that they are probably 3 generations removed from the negative.
O-neg
Interpositive (IP)
Internegative (IN)
Release Print
Since Star Wars was so successful, there were several Interpositive prints struck over its lifetime. From these, many more Internegatives were struck, since they would get worn out during the production of release prints.
Now if we had access to a good IP or IN the work would be greatly reduced, though these prints were usually too worn out to be much use. Barring this, we have to use release prints. Dye cloud mapping of several release prints should produce an accurate image of the Internegative that produced them. Since there were probably several internegatives made of each interpositive, the release prints would have to be organized by the internegative that made them, and the process applied to those groups separately. Perhaps you can see where this is going. Say you need four versions of a single frame from prints generated by a single internegative to correctly recreate the internegative grain. In order to recreate the interpositive grain, you’d need to have four fully recreated internegatives, and to recreate the grain of the o-neg, you would need four fully recreated interpositives. All told, 64 release prints from the various IPs and INs would need to be correctly identified, scanned and mapped. It’s quite absurd.