Lots of old TV pilots failed outright, but some had enough promise to be re-written, re-cast, and tweaked until everything clicked. Famous examples include “Star Trek,” “The Dick Van Dyke Show,” and “Gilligan’s Island.” Less well-known is the false start that my all-time favorite series, “Leave it to Beaver,” had with “It’s a Small World.” Look for Harry Shearer in a role that seems to have been a precursor to Eddie Haskell.