I never noticed this before, but at the beginning, June asks Beaver what he's going to do today. Beaver replies he's going over the Lumpy Rutherford's with Whitey and Gilbert, to wash Lumpy's car (Lumpy is charging them to do it, an idea he probably got from Eddie).

It ended up being Whitey and Larry. I think Rusty Stevens had already been given the boot, and his 2 season 4 appearances were probably because another actor was sick or something (in this case, S. Talbot).