I recently received this information in an email from Chris Comly.
A very nice CX7A with an equally nice CX7S.

My name is Chris Comly, KA3EAQ. My father, N3AOG, owns a CX7A that I believe was upgraded to a CX7B. 
Serial Number from the data plate in the back is 039228386. He also has the speaker. 

The radio was originally purchased by our neighbor, Don Austin. Unfortunately I have no idea what his call sign was. He became a silent key in the early 80s. 
That is the best I can tell because I graduated from high school in 1982 and that is about when I stopped being active as I have never used the Signal One. 

As far as I can tell the radio is fully functional. There is presently no antenna available to check. I cannot say the last time my father used it but it could be 20 years. 
His interests had moved to the uhf and higher frequencies at that point and has equipment in the gigahertz bands.