Two kids tell how their dad's gift of a meal to the homeless man who sleeps outside their neighborhood store leads first to an informal exchange of his help (sweeping the sidewalk, etc.) for more food and eventually to his going happily away with his parents, contacted through ``a big office.'' Barbour (who illustrated Adoff's Flamboyan, 1988) is a gifted artist whose vibrant colors and comfortably rounded forms are not especially appropriate to the topic; and while the kindness and respect shown towards this troubled veteran (whose name proves to be ``Elliot Lyman Bristow'') are laudable, the conclusion is unrealistic: jacket copy reveals that ``the real Mr. Bow Tie remains on the streets.'' Well-intentioned but simplistic. (Picture book. 4-8)*justify no*