A 'blue plate special' is a colloquialism referring the practice of diners and restaurants offering a low-priced meal as a daily special, usually presented on a divided plate (usually blue in colour). The meal was usually some sort of meat and three vegetables.
The Fuller Brush Company was noted for door-to-door sales of brushes of various sorts, with many Fuller Brush salesmen door-knocking houses all over the USA. There were two movies made - The Fuller Brush Man and The Fuller Brush Girl.