Sweeney Todd

Why were the accents so off in the original Broadway production of Sweeney Todd? Mrs. Lovett is consistently Cockney but the Beggar Woman goes back and forth between Cockney and not (alms, alms...), although I think she's fairly consistently Cockney in her spoken lines--and Sweeney himself has an American accent! And Anthony's accent seems awfully posh for a common sailor. Confusing...