American Electric Co. "Sonoscope"?

[citydweller]

This is a "sonoscope", a nifty little stethoscope-type device invented around 1900 to listen to plumbing & sewage pipes, boilers, conduit, small engines etc for audible issues.  Used by plumbers & furnace folks mainly, also called a "water phone".

However, all of these that I could find were made by a W.S. Darley, and unlike this one do not use an American Electric Co. ear piece shell.

Did American Electric make some of these at one point?  I can't find any.