I sympathize about your cel, and I honestly hope 
you'll be able to salvage it at least somewhat.  
Shame what the post office does sometimes.  I 
literally tore my hair out earlier this week when 
I returned an order that had been incorrectly 
shipped to the dealer and realized afterwards 
that I had forgotten to write "Do not Bend" on 
it.  Thank goodness nothing happened, but it was 
still a hair raising experience.

I've been very lucky so far, the worst damage so 
far done to a cel (an ultimate wishlist for that 
matter) was a tiny tear in the paint on the edge 
of a background where the glue got stuck to the 
background.  That was such a frightening moment 
where I attempted to pull them apart, and I was 
incredibly thankful that only a tiny piece of the 
paint came off.  Close call though.

Again, hope everything works out for you. ^_~  
Proof, though, why every package needs a little 
insurance.

-Chaotic Serenity