“Seinfeld” was one of the best TV comedies of the ’90s for many reasons. In addition to whip-smart writing by Larry David, an indelible cast of ne’er-do-well lead characters, and outlandish plotlines which were essentially “about nothing,” it was the revolving cast of oddballs and weirdos who circled the world of Jerry and his friends that gave the show its signature flavor. These unique roles were often performed by notable character actors, some of whom had been recognizable faces for many years in the Film and Theater world, and some who caught their big break on this hugely popular sitcom. This week, we sit down with the actors behind two of the show’s most memorable characters: the overly anxious Mohel from “The Bris” episode, played by the late Charles Levin, and Lt. Joe Bookman, the hard-nosed library cop from “The Library” episode, played by veteran film actor Philip Baker Hall of “Boogie Nights” and “Magnolia” fame. In these two wonderful and insightful interviews, we discuss Jerry’s inability to keep a straight face while filming, the network’s lack of confidence in the show at the beginning (they thought it would be a dud), and the struggles of trying to make a living as a supporting actor.