The only problem might be doubt about it's 
authenticity *if* this stuido has stickers on all 
it's cels. If the studio doesn't have stickers on 
all the cels, I can't see the problem. Not to 
mention you do still have the sticker and if you 
ever did want to resell the cel, you can always 
simply note that you removed the sticker for 
asthetic(spelling optional) purposes.

Many Sharp Smiles,
--Drac