Bad repro is an issue that really bugs me. Personally, I would be more than willing to pay a higher price for my books if more time could be spent on them to bring them up to a good standard. Do others agree?
If the original art is unavailable and the negs are lost/degraded then there’s relatively little that can be done short of basically re-drawing the affected areas. Even then, with nothing nothing more than a poor-original-copy prog for reference, what you’re going to get is some hapless sap’s best guess.
For tiny areas (like the relatively small amount of re-drawing I did round the edges of the new speech balloons in Charley’s War), you can (I hope!) get away with it. For larger areas, you’re asking not for re-touch but an artist who can convincingly imitate Bolland, or Talbot, or Ezquerra… and that’s going to add a time and cash overhead that’ll have more than a marginal impact on the price of the end product.