Oh, I see what you mean about an appraisal, sorry, 
I misunderstood there. But, the post office will 
take your word for it that the cel is damaged, even 
if it's only a tiny paint chip; you don't need any 
kind of paper work to prove it.  They really don't 
care and they most likly won't give you an argument 
at all.  I once filed a claim on a toy I got, where 
the box got dented a bit in transit.  The postal 
workers didn't care, despite the fact that to the 
none collector, a box gets thrown in the trash 
anyway.  And they even let me keep the toy, which I 
sold on eBay later, because it was useless to the 
collector in me, unboxed.