It would appear that Gun Broker has started mandating that dealer accept transfers from non-FFL senders or you can't advertise as an FFL.

I stopped accepting from non-FFLs after getting firearms with no ID from the sender, too much trouble trying to contact the sender and get their ID.

So, for those that I do GB transfers for, I am sorry to say I will no longer handle any GB transactions. Not a spoiled sport just tired of all the and rules.