A stack of two food cartons can be seen in the open refrigerator when Wally is talking to June. In the close-up shots that show just Wally, there are three food cartons in the stack.
When Eddie is shown changing the grade, it looks like an older person's hand.
When Ward is reading Beaver's report card grades to June, he does not mention Beaver's grades in "Deportment", "Art", "Music", or "Physical Education". This is also true when Eddie reads Beaver's grades to Lumpy.
Before Eddie and Lumpy enter the den, Eddie is wearing a ring on his left hand. When he stands up from the desk, the ring is gone.