[Gimp-user] Scanned negatives, moire patterns and GIMP?

["Keith Purtell" <keithpurtell keithpurtell com>]

I recently had some 20-year-old color negatives scanned. About half the 
scans had moire patterns. My understanding is that moire (in this case) 
would be caused by contact between the glossy back of the negative and 
another flat object such as a glass plate. When I went back to the 
photography service, they told me their technician had reported the moire 
was because "the negatives are really old." Well yes but they've been 
stored in dry archival conditions and are not visibly damaged. They said 
they'd try again.
  
 If they can't resolve this, what are my chances of solving the problem 
with GIMP? I tried a few of the existing filters without visible results. 
My first Google searches haven't turned up a good detailed tutorial on 
moire removal.
  
  EK