Hi Robb,
Maybe you have an answer to this?
Discogs have linked Mike Williams to Jimmy Williams who were in a rock/beat group during 1965/6 called 'The Playboys Of Edinburg'. Later, the brothers formed a country outfit called 'The Younger Brothers'. As you can probably work out, these are white musicians. However, as Mike Williams also had a 45 out on 'King' which is a James Brown production, I have my doubts!
Begs the question: if Mike is a white guy... 'Vietnam Through The Eyes Of Black America'.??