Middlefinger Fitzgerald’s Friday, March 10 What you see is not always what you get with Middlefinger. But the initial observation helps. The short-cropped hairdos, black-rimmed eyeglasses, intentionally shocking T-shirts and the bleached-out blond guy, David Cummings — stage right, far stage right — with the ’80s-metal Ibanez guitar strapped around…