The claim could be audiovisual or audio only, and might be for the whole video or just a few short segments. The claim might also apply different policies based

The claim could be audiovisual or audio only, and might be for the whole video or just a few short segments. The claim might also apply different policies based on territories (public domain in the US does not imply it is public domain worldwide). If you are sure about it, then dispute the claim, and dispute the next one if necessary, even if that’s under DMCA. Then all they can do is file a lawsuit, which they won’t do. Full disclosure: I worked with contentID for the past 10 years.