Lurch's costume was a 'Little Lord Fauntleroy' suit. The 1888 book of that title was so popular and depicted the clothes in such detail that the style became a major fashion trend.
In the scenes in the playroom where Gomez and Lurch are on the rack, there is an empty frame on the wall. This frame is actually a piece of tramp art, a frame made of crisscross notches made with a pen knife out of cigar boxes.
At the dance, when Lurch is sitting alone, the others are all dancing to "Uncle Fester's Blues". When Lurch dances with a disguised Morticia, they do so to "The Anxiety Tango". Both songs are represented on Vic Mizzy's soundtrack album "Original Music from The Addams Family."