As seen in the two pictures above, one way to identify this action is by the "O/H" insignia, which is found inside the spoolbox on the metal patent plate. This action was made in New York City. The "Metalnola" shown below may have worked very well, but apparently did not endure. Touted as "The Player Action of the Future", the intricate and somewhat complex die cast valve chambers typically suffer from warping and cracking. Therefore, it's always best to inspect the player system thoroughly before buying it or agreeing to rebuild the action. The later type is far more common and was produced until the late 20's. The novel feature of this type was the individual pouch blocks that are clamped over the wooden valve seat, which could easily be removed to expose the small valve (which was similar in form to the Pratt-Read valve). The valve was speared over a center guide pin.

Otto Higel Valve Parts (1920's Type)

Exposed Valve Chamber (1920's Type)