The acquiring of a "signed copy" of a FFL is not a law. The law is that you must ship to a FFL. Having a "signed copy" is one way that has been accepted by ATF of you having done due diligence to comply with the law. But it is not the only way.
The online verification is another accepted method.
But none of it matters. You are not bound by law to any method of verification. You can simply send based on verbal, reputation, or gut instinct. The only thing that matters is that you indeed send it to an FFL. The "accepted method" only comes into play if you sent it to a person/address that turns out to not be an FFL holder and you are being investigated. For example, you or I may decide to send a gun to Remington or CSM for repairs. We may be very confident of them having an FFL and we send the gun. There's no violation of law. We sent it to a FFL.
