Gregory's Server@rrrrroseazerty Wow, that's complicated! I only deal with YouTube, but have dealt with Content ID claims on recordings I've made of old music, not covered by copyright. Each time so far, it's been successfully solved through the built-in appeal process.
I assume the reason you're taking the longer route is to get rid of it from all platforms at once?
@rrrrroseazerty
So far, my experience has also been different in that the claimants hasn't been random trolls, but major music publishers. (Most likely because they've published another recording of the music and lazily vacuumed up all rights, including those they don't have.)
As I said, the appeal process has worked for me, but I doubt I'd be able to make contact with someone like Sony using your method.