Source for historical recordings --Edison, etc.

I just read Greg Milner's Perfecting Sound Forever, which I highly recommend to any serious audiophile. It caused me to be very curious to hear some of the earliest recordings, particularly the "acoustic" vs. "electrical" recordings from the early days. A CD companion to the book would be the bomb (including the Led Zep stuff, early sampling, Auto-Tune and all the rest), but absent that, the early wax, cylinder and disc stuff must have been transferred to CD and be out there somewhere. Any pointers?