[Heathkit] Looking for Microphone Info

[Receiver]

Some time ago, I bought the remains of a ham's radio stuff that had been 
donated to a local boy scout troop.  It had a Heathkit desk microphone in 
it.  The microphone looks as if it was made by Electrovoice, as it looks 
exactly like the EV-619 & 719 models.  Can anyone help with any information 
about it?  I have an info sheet for a Heathkit microphone that was used with 
an SB-101, but that is not the one I have.

Thanks in advance for any help you can give me.

73, John, W4NET