The place I contacted sent me a booklet of things 
they've done as far as restoration on cels. They 
had gotten a cel of the evil Queen from Snow 
White that was horribly damaged.  I have before 
and after pics, it's quite bad.  The original 
painted bg was almost completely faded, and the 
queen had very little paint left.  After the 
restoration job these people did on the cel...it 
went for 58,000 dollars at auction.  That cel was 
worth about 1/20 of that amt without 
restoration.  I dont see a problem with selling a 
damaged cel with proper work done to it for a 
nice price.  It takes unbeleiveable time to do 
this work. If you could read about how it's done, 
you'd agree, I have no doubts about that.