By Rob Cox NEW YORK (Reuters) – The velvet curtain had yet to open at the Ritz night club in New York’s East Village when the opening riff of Aerosmith’s “Walk This Way” thundered over the rowdy crowd. Paul Westerberg emerged stage right with a guitar strapped around him before the curtain parted, and the Replacements, long on critical acclaim but without great commercial success, played what punk rock cognoscenti regard as one of the greatest concerts ever. That show, on June 21, 1986, was sloppy, raucous and unpredictable. …