Unfortunately, as it was the tape recorder that was lost or stolen, about 45 years ago, the tape in it was probably unwittingly recorded over. Whoever acquired the tape would be unlikely to realize it's value.
But with Randy confessing to making "bootleg" recordings, I can't believe that the only one he made was lost. He must have more. I suspect that Randy will have some illicit recordings from his lengthy career stored away somewhere
I'm surprised that Randy didn't know anything about Bill Szymczyk's Soul Pole LPs.