Looks like a Piezo Electric Loudspeaker stamped LX21 and 26021 from the early 1930s, but it's not.

Thanks to Scott's reply below & others to my earlier video.

It's not a piezo, it's a moving iron electrodynamic. The package at the back has two soft iron horseshoe magnets which create the magnetic field for the motor. There will be a coil of wire wrapped around a springy, soft iron armature, and this moves when audio is fed into the speaker from the output tube. This coil is connected between the power supply (the + terminal on the speaker) and the plate of the output tube (the P terminal on the speaker). There is no output transformer. The levers you refer to magnify the small movements of the armature to more efficiently drive the cone.

In addition, check out my earlier video and others where I introduce the Simplex, model PB mini-cathedral dual-band receiver I acquired about nine years back that's been in storage. The seller at the time told me the radio was from a family in the Charleston, SC area; other than that, I don't have any other information on the history of the receiver with the exception of the Simplex factory was located in Philadelphia, PA then later moved to Sandusky, OH where the company was purchased by Philco and the plant was closed shortly after.

The playlist for the Simplex Model PB restoration:
   • Simplex Model PB | Restoration Series  

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