This is such a coincidence - I just copied the recipe this week from Woman's Day magazine, July 14, 1998. They featured popular recipes from Disney resorts including the grapefruit cake from the Brown Derby. The recipe you posted is practically identical to the one in the magazine except that the frosting was made with 2 packages of cream cheese, 8 oz. each, not 3 oz. Also after beating the frosting they gently stirred 2 tbsp. of finely chopped grapefruit segments into the frosting.
They put thin wedges of grapefruit on top of the frosting sandwiching the cakes and garnished the top with remaining grapefruit segments and candy confetti.
They suggested using Ruby Red grapefruits which looked pretty in the photo.