virginian: There are 14 unreleased songs, per RA's claim. That is enough to make a cd that can include any of those that weren't copyrighted, which is a stretch to assume that they'd cut a master tape of songs they forgot to copyright.
As for being worth alot to whoever owns the Jackson catalog, I think it is pretty safe to assume they have their own set of high quality recordings, probably digitally enhanced and saved on digital media, which could explain why the 'master tapes' are kicking around.
Good luck with that. If those 14 songs aren't copyrighted, he might have something - assuming that the reason they never copyrighted and released them wasn't because they sucked.