There's a short 10 minute audio interview with Chris Strachwitz and a bit of information on Nathan Beauregard at the link below from the Arhoolie foundation...
https://arhoolie.org/nathan_beauregard_interview/?fbclid=IwAR2b9BzbVAwL1vxCeTPA3afhfD54z1yVN-NFA6PVwuIro-bExwlh9xcXdqA
Also from the film Good Morning Blues presented by the Mt. Zion Memorial Fund from "Good Morning Blues"
https://arhoolie.org/nathan_beauregard_interview/?fbclid=IwAR2b9BzbVAwL1vxCeTPA3afhfD54z1yVN-NFA6PVwuIro-bExwlh9xcXdqA
Also from the film Good Morning Blues presented by the Mt. Zion Memorial Fund from "Good Morning Blues"