I sold a lower AR-15 Assembly to an individual on Gun Broker. I do hot hold an FFL, but I shipped it to an FFL for the buyer. Now the buyer's FFL won't release the lower assembly to the buyer, until I send the buyer's FFL a copy of my drivers license. The buyer's FFL says it is a federal law that I include my drivers license. I could not find anything in BATF rules that say I have to include a copy of my drivers license. Does anyone know what the ruling is?