This ATB probably is copyrighted (Score 1)

I agree that Rumblefish is probably a content ID troll that makes incorrect copyright claims all the time. It's very common these days and a huge headache for content producers to have to swat away these illicit, automatic claims. However, this composition is probably not in the public domain. The arrangement by Carmen Dragon was made in the late 1950s and is still well within the time window to be copyrighted. (Yes, arrangements of public domain works can be copyrighted). The source of the claim, this "sookietex" that uploaded the Navy Band recording to archive.org, likely without permission from DoD or the Navy Band, has extremely questionable legitimacy for making such claims and shouldn't be quoted as an authoritative source for anything. So the actual copyright holder, whomever that is, would be entirely within their rights to monetize this video themselves or even demand that it be taken down.