Well, I'm not a lawyer nor do I have any legal 
background, but I can offer you another scenario 
which may or may not apply to your question. But 
it's food for thought.

In dentistry, the dentist has a record of all 
your dental records, procedures, medical history, 
etc. Now, the record itself belongs to the 
dentist, but the information contained in the 
record belongs to the patient. So the patient 
can't take the original record for himself, but 
he can request a copy of all the stuff inside. 
Nor can the dentist copy the record to give to 
anyone without the patient's permission.

So if you apply this analogy loosely, then you, 
the cel collector, are the dentist who owns the 
cel, which is the dental record. But the image of 
the cel is analogous to the information inside 
the record. Thus, if you wanted to make a copy of 
the image for whatever reason, then you would 
first have to ask the studio or artist for 
permission. Make sense?

Ahhh, I think I need some sleep. Just a thought...

Tony