}}} If there are actually still 3 unidentified wires going to it,
you need to ask yourself what the other two are as well. {{{

Good point! I have to assume they were unused, as there were no other mike
functions. I can get to the backside of the unit. But, if those pins are
used, I won't know what they go to in the solid state mess.

}}} All that you then need to
do, is touch each of the three unknown mic socket pins with the tip of a
screwdriver, with your finger on the shaft, and listen on the monitor
receiver, for the pin that produces a buzz. You've then found the mic-audio
pin. {{{

Excellent idea!!! The feedback buzz should do the trick nicely.