exactly what nostr:npub1pu3vqm4vzqpxsnhuc684dp2qaq6z69sf65yte4p39spcucv5lzmqswtfch said. once you have the hash you don't really need to find the owner.
However assuming you wanted to find the owner so you could send them some sats. you could search the nostr protocol for any 1063 events and who they where signed by. then filter that down by your WOT. That would show you who in your WOT "claimed" to own the file
