I would *NEVER* worry about the cel being fake.  
It was bought from a reputable dealer, who bought 
it from Anime Link in the first place.  The cel 
AND drawing both have the AL stamp in the upper 
right hand corner.  

The cel may be missing a correction layer, but I 
see no evidence that it ever had one.  No paint 
flecks on the top of the cel...No staple 
holes...But that's not saying it couldn't be 
missing one.  I probably have a few more in my 
collection that were altered by computer after 
filming, but I know of one that was used for 
special effects...My Sawa cel.  The white 
triangles in her retinas were almost completely 
shaded out for an effect, while they are a 
seperate solid white layer on the cel.  Look at 
the sketch...They aren't even drawn in 
there...Just like on the Charlotte cel.

Whatever the case...It really doesn't matter to 
me.  I'm happy with it, and I've checked over my 
dvd with a reliable program.  It's a KEY cel, and 
has about a 3 second hold on the screen.  It's 
the same set-up for the whole sequence too...The 
dealer I bought it from had another from the 
sequence, and I'm positive they both are real.  
Probably won't ever really know what happened, 
but that's all right with me.  I know what I've 
got ^_^/!

Thanx for your comments all(and concerns ^^')!