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 (1948) and The Fuller Brush Girl (1950).
Although two entirely different stories, this film and Mexican Spitfire Out West (1940) released one year earlier, both begin on Carmelita and Dennis's first year wedding anniversary.