Having spent some time digging for information, I've come to the conclusion that the Bayou Blues Band never actually recorded together. Possibly it was just an idea that came to nothing.
Cathy Chemi (mentioned as featuring with Randy Hart in the group) is a jazz vocals with a long history and a very respected reputation. However, I can find no reference to her and the group at all.
In fact, there seems to be no mention of the group beyond the mention in the Record World article (groups have existed with the name Bayou Blues Band, but these don't appear to contemporary with Magid's announcement.
I did find an archived text listing of an ad that appeared in Cash Box magazine 03/07/1971. That clearly associated Hart with his Cajun nickname.
I tried to see if I could find out any more info by checking out people Hart had collaborated with. The only thing of interest that I found was a snippet in a publication produced by The American Federation of Musicians and called Report of Officers to the Annual Convention (Volume 70, parts 1967-1972).
Ray Rachaels was a member of the group The M-3's, which comprised Rachaels, Hart and Bob Bryant.
Just to confuse matters further, entries for Randy Hart in the Catalogue of Copyright (3rd edition) state that Randy Hart is a pseudonym for Gerald Randolph Hard (Hard is a typo as other entries show the name as Hart).
But is this the same Randy Hart with the Cajun nickname or a different one?
Searching for Gerald Randolph Hart brings up records of a person, aged 80, living in Florida. Could it be the same songwriter? On the other hand, the court case snippet shows that Lee Magid's Randy Hart was a member of the musicians union in Columbia, South Carolina - a completely different part of the country.
Mind you, people do move...
Anyone got anything else?