...you might not actually need to sell 
anything.  All major credit cards have some sort 
of fraud protection, to keep you from having to 
pay for somebody else's crime.  Your first step 
is to contact the police and fill out a report.  
Then you can take that police report number to 
the credit card company, and file for fraud.  
This happened to one of my relatives last year, 
and while it took a couple of months to sort 
out, the only thing he ended up paying for was a 
$60 restaraunt charge that he wasn't 100% sure 
wasn't his, since he'd eaten there occasionally, 
although not lately.

Check out your options before parting with 
unique treasures like those cels, and you 
certainly have my empathy for your situation!!