Success.
I reinstalled ofono and rebooted the system. With a different set of
headphones (Inland # 87099), the microphone worked at
https://mictests.com and
https://onlinemictest.com and when going back
to YouTube, I am getting the audio from that, however the sound is not
as powerful, almost monaural (not really full stereo). But at least it
works now.
I will try this with the Sentry headphones, once its battery recharges.
Thanks for the assist.