Not to poke my nose in here, though I am. Let me ask you this: do the brother's notes include information on your ancestor? If so, and if you're using Legacy 8 then maybe you can consider moving the notes to an event, then sharing that event with the brother that is your ancestor. I'm fairly certain that the shared event will show up in the ancestor report.
I understand your problem though. Many times notes include information on other family members. For years, I've wondered why we can't share certain notes. To fix the problem, I've created a new "event" called Notes with absolutely no sentence definitions. This way I can do what I want with it. I move those to the top of the events unless a date is necessary.
The only problem with sharing is that it also includes a "role". To alleviate that problem, I created a role called Notes and then I left the sentence definitions to that blank as well. So when you share John's notes with Tom's, then Tom's role is Notes.
Hopefully that makes sense.