Yea, that don't make any sense. Every copy of an FFL license I've ever seen was signed by the FFL holder. How can you sign something that is already signed?
I've had the best luck buying firearms online when the local FFL dealer is already on file with the seller. I've had the worst luck when I had to get the local FFL dealer to fax/email a copy of their FFL to the seller. I purchased an SKS rifle on GunBroker once and asked my local FFL dealer to fax a copy of their FFL to the seller. I kept checking with the seller and they kept telling me they had not received the FFL copy. I called the local FFL dealer several times and they said they had faxed the FFL several times and was not going to fax it again. Turned out, the seller's fax machine was broken. That scared me and gave me phobia about buying firearms online and having them shipped to a local FFL. Now, I will not pay for a firearm online until I know for sure they have the copy of the local FFL dealer I'm using, cart before the horse or not.