Anybody know what this is?

[Lynn Wheelwright]

I have had this one for a while and decided to try and figure out how it works. Looks to have been made for the National EH it is attached to but seems far too well engineered and built to be one-off. The larger disc moves up while the smaller one moves down. The way it is strung only the larger disc produces any pitch change. If yu have any ideas or know about this please chime in. Thanks

[Tony Oresteen]

Perhaps it needs to be traveling at 88 MPH before the dials work....

[Jack Hanson]

1930s steam punk?

[Eric Dahlhoff]

Fascinating!

[Jon Light (deceased)]

Wow.
I'm trying to make out whether it has a locking device to be a tuning changer a la the Dobro Hipshot that toggles between two presets or if it is a playing device.

As much as you, Lynn, are a walking encyclopedia, it strikes me that if you have never seen one of these before, the odds that there might be yet another one in the world seem slim.
IOW I lean toward it being a very elaborate one-off.

[Richard Sinkler]

I'm thinking possible palm pedals. Certain strings are attached and it has springs.

[Jerry Overstreet]

Appears to be a device to change complete tunings, say from open D to Hi G, etc. Since you say the discs move in opposite directions. I'm trying to determine how the big knob enters the equation.

Also the lettering reads Chord Production which also leads me to believe it's purpose is to change entire chord tunings.

Whatever it is, it's a good way to mess up an otherwise nice old guitar.

Still trying to figure it out.

[Paul Strojan]

It looks a lot like the Edge string bender that Jackson's make. As designed, the levers rotate set screws onto the strings to raise the pitches of the strings. It looks like big circle was designed to raise strings 2, 3, 5, and 6 consistent with a E major to A major change (E, B, G#, E, B, G#) to (E, C#, A, E, C#, A). The small circle I am not so sure of. It only acts on strings three and six. Also there is a spring underneath the lever that looks like it is working to keep the strings up. Too me, it looks like it is a lower perhaps to E minor (E, B, G, E, B, G).

[Bud Angelotti]

Looks pretty elaborate for a one off.
From Upper Darby Pa.too.
You know who's from Upper Darby?
W.C. Fields.

[Bill Groner]

You know who's from Upper Darby?
W.C. Fields.

AND...Tina Fey, singer songwriter Jim Croce, instrumentalist Todd Rungren

[Anthony Maurer]

Is there a patent number anywhere on it?

[Dan Kelly]

At any rate, nice clear photography. Good pics!

[Andy Volk]

I have never seen anything like this. Good mystery!

[Steven Wilson]

Who made the guitar? The hardware looks like an early version of palm benders, but with the placement I can't imagine they were easy to use....

[Steven Wilson]

Actually, when I zoom-in I see it is a National; maybe from the mid 30's. It's a cool instrument, but only you can judge functionality if those are benders....