By Eric Twardzik As far back as he can remember, Scott Fraser Simpson always wanted to be a gangster. Or, rather, dress like one. The vintage-loving British designer’s eponymous clothing line could be described as “wise-guy chic,” with wide-legged pleated trousers and knit shirts aplenty. And while his limited-edition clothing was often inspired by vintage pieces, some very particular knit shirts had eluded his grasp — until now. “I’ve been collecting Italian-American knitwear for over 10 years now, and there’s always those elusive pieces that you know of, the ‘Holy Grail’ types,” Simpson says…