Astatic D-104 Microphone

The vernable D-104 by Astatic must be the best recognized ham microphone ever produced.  I shall add more information as I gather it. 

Here is my stock D-104.  Notice no PTT on the base or the stem!  I acquired this as a basket case from eBay for 15 dollars and restored it.

Here is the response curve of the non-amplified version.