Occurred to me this would not be that difficult to re-create.
Use a servo to create the original trace. Need to think on best way to read back - hall effect sensor with ADC? Start with a sine wave.
... bandit

http://edison.rutgers.edu/tinfoil.htm

Tinfoil Phonograph

Photo: Edison with Phonograph. In July 1877, while developing his telephone transmitter, Edison conceived the idea of recording and playing back telephone messages. After experimenting with a telephone "diaphragm having an embossing point & held against paraffin paper moving rapidly," he found that the sound "vibrations are indented nicely" and concluded "there's no doubt that I shall be able to store up & reproduce automatically at any future time the human voice perfectly." Edison periodically returned to this idea, and by the end of November, he had developed a basic design. The first phonograph consisted of grooved cylinder mounted on a long shaft with a screw pitch of ten threads per inch and turned by a hand crank. Instead of paraffined paper, Edison used a piece of tin foil wrapped around the cylinder as a recording surface. The first phonograph had separate recording and playback mechanisms, but later designs combined them into a single unit.

Satisfied with his design, Edison had machinist John Kruesi construct the phonograph during the first week of December 1877. Edison later recounted that when he explained to Kruesi that the machine was going to record and playback speech "he thought it absurd." When Kruesi finished making the phonograph Edison put on the tin foil and then recorded the nursery rhyme "Mary Had a Little Lamb"; Edison's daughter Marion was at the time nearly five years old and his eldest son was almost two. Edison then "adjusted the reproducer and the machine reproduced it perfectly. I never was so taken back in my life. Everybody was astonished. I was always afraid of things that worked the first time." Similar astonishment occurred the following day when Edison exhibited the new invention at the offices on Scientific American.