Gem roller organs were made by the Autophone Co. of Ithaca, NY from the mid-1800s to the 1900s. This is a very early model; later ones have an enclosed bellows. It is also known as a cob organ because the music is provided on a cob-sized wooden cylinder with inserted steel pins. As the cylinder rotates, the pins press the valve covers to open them.
One of the least expensive organettes, it was advertised in the Sears catalog for $3.25. It has 20 notes.
(photo provided by Harold Draper of Roller Organ Restorations)