Not quite sure about this statement. It implies that the veteran would have been OK possessing “an unregistered serial-defaced automatic weapon” if he had a Class 3 Federal Firearms License.
I don't think a Class 3 License allows for the possession of serial-defaced weapons, or the possession of unregistered automatic weapons - by the veteran or anyone else.
Further, the statement may imply - doesn't say it outright -
that a person needs a Class 3 Federal Firearms License to legally own an automatic weapon.
That is not my understanding. To legally own a machine gun, a person does have to complete a lot of paperwork ( two original copies of ATF Form 5320.4, often called Form 4 and two FBI/NFA fingerprint cards, and ATF 5330.20 citizenship certification) and wait for ATF to approve by attaching the $200 tax stamp.
If the “person” is a corporation or trust the paperwork is a little different but I don't keep up with those details. A machine gun dealer must have a federal firearms license, but a non-dealing person legally purchasing a machine gun does not need a Class 3 Federal Firearms License - just has to jump through the hoops and pay the tax.
I believe you are quite right. I formulated the sentence in this form to include at least three violations of federal law. What makes the irregularity of a ground-off or illegible manufacturer's serial number unlawful is possessing the defaced article; that is, having it in one's control, care, and keeping, By having it within one's purview, he/she also has accountability for being knowledgeable of its state and condition. That does not necessarily mean having title or ownership of the item. It could be keeping it secure as a favor to its owner, even overnighty.
As I read it, the purpose of the class 3 license is that it permits one to lawfully possess a firearm covered by the law. If one has an unlawful firearm in his possession without promptly notifying the authorities and surrendering it to them when requested, my understanding is that the possessor is then subject to citation for the infraction, as well as having the item confiscated.
I would be pleased for you to correct me if this sense of liability is wrongly perceived.