1975 Guthrie Concert Recording

Hello all,
I am looking for a recording of Michael's Guthrie concert from June 22, 1975.

Minnesota Public Radio recorded it for their folk music series but never broadcast it and they say they no longer have the reel to reel tape - they said many of the folk series tapes "disappeared". I've also checked with Walker Art Center and the Guthrie.

If anyone has any kind of a recording of this show, please contact me.