Yes, they would have to be registered to sell, that wasn't the question though

The question was where is the seller registered (as in which country)

And eBay will protect you IF you open a dispute for item not as described, if what you were sent does not match the photos/item description

No, they won't 'just take your word for it' that you 'think' they are fake

That is a different thing entirely 

And again, what is the item number?