Even amateurs (or their estates) are entitled to a cut, if there is any income involved. There is also the copyright issue, for all their arrangements and original works. Real collectors/archivers have performers sign releases detailing how the recordings can be used. Failing this, you're always putting yourself at legal risk trying to make such recordings available, even at no charge and for what you consider "educational" use. You may have to let the recordings languish until all copyrights have expired (long after you have.) Sorry, but the laws were designed for the benefit of media conglomerates, not for the good of the public.