Lost pilot on frequency

It was July 2, 1974, and my wife Mary Ann and I were flying home from Salilsaw, Oklahoma where we had dropped off an employee’s children. I was just north of Guthrie, Oklahoma; it was early evening and near sundown. We had our Beech Debonair cruising in smooth air at 7500 feet when a call came over 122.8. “This is Cessna NN; can anybody hear me?”