Off the subject of the seller, are you looking 
to get a full or partial value recomp for the 
damage?  If the cels are not completely 
mangled/still viable, you might want to see 
about geting an actual appraisal for how much 
the damage has impacted the value.  You'd have 
better luck claiming a smaller amount of money 
with the insurance mix-up, official 
documentation would support your claim despite 
the insurance mix-up, and if you claim for the 
full amount, you don't get to keep the cels (the 
PO does, and there is a very good chance they 
will simply destroy them)