June tells Beaver that Fred Rutherford had to take Violet to her ballet lesson. Beaver says Violet is practicing to be a famous Broadway star, but Larry told her they wouldn't let anyone be a Broadway star with braces on their teeth. But way back in The Black Eye (1957), Violet had already had "$800 worth of braces!" removed.
When Andy asks Beaver for a drink, he states that it's hot outside, yet Andy is wearing a sweater and Beaver a jacket.