Mystery Horn from 41 Schwinn

[Old Iron Bob]

This horn was on a 1941 Schwinn. It is a small diameter Bakelite or plastic button. The sheet metal looks like a Delta or EA. I posted photos of a few different horns.Has anyone come across a horn like this?

 

[Old Iron Bob]

I tested the fit on a postwar tank. Fits good.its a little loose in the prewar tank