Second-edition familiars were an entirely different thing from 3rd or 5th. In 2nd, you had huge penalties when a familiar died... but as long as the familiar existed, the wizard got an increase to their own HP. So the optimal way of using a familiar was to write down in your backstory that you cast the spell once, write down your improved HP total, then keep the familiar hidden away and forget that it ever existed. Which wasn't very interesting.