Holtzer Cabot headphones
 

I'm looking for an owner's manual OR any related literature (magazine
ads, etc.) on Holtzer-Cabot headphones, circa 1921 through 1926.
Here's a link to give a general idea of the type headphones I'm
talking about:
http://members.aol.com/oldradjo/galleryh.html
If anyone has any literature they'd be interested in selling, please
let me know! An owner's manual would be ideal. But I'm not too fussy.
Thanks in advance,
Bryan Lord
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