Actually, my brother looks exactly like Chevy Chase, circa 1984. In fact, my brother hates with a passion the National Lampoon Vacation movies. Once, when I was visiting several years ago, we were sitting in his living room "talking" (actually, he was having one of his soliloquies) when the National Lampoon's Vacation (the Wally World one) came on. He got up, turned off the TV and said "no, no, no I hate these movies. They're soooo stupid." I think he must recognize the resemblance. I mean, Clark Griswold could be his doppelganger. In fact, I secretly refer to him as Clark Griswold's evil twin. He's klutzy, has weird ideas, things always have to go his way, family gatherings usually turn into disasters, and then he has a complete meltdown. But usually there's no denouement where he has a wisdom-filled epiphany, and no happy ending. Usually, he just picks up and quietly moves off, ranting and plotting revenge...which never materializes.
Perhaps a good title could be: National Lampoons: The Legacy.