The rest of the sources can be found via Ross Anderson's page. Note that many webpages assert some sort of vague right over the scanned versions of these MSS: you can safely ignore these, as no such rights exist (Google Corel v. Bridgeman for the gory details). Out of copyright is out of copyright. Note that an arrangement can be copyrighted, and therefore we cannot simply scan copies of the PS collection (although that said, the earliest books should be out of copyright by now?).