In a medium bowl, stir sherbet, 1/4 cup liqueur and orange rind until well blended. Cover and freeze overnight.
Cut rind from oranges, removing all white pithy material. Slice oranges thinly and sprinkle with 2 tablespoons liqueur. Cover and refrigerate.
To serve, arrange orange slices on eight dessert plates. Top each with a scoop of sherbet. Pour about 1 1/2 tablespoons of the sauce over each serving.