The macabre execution of a Hyde Park man whose mouth was sewn shut and hands bound behind his back before he was fatally shot in the chest has moved homicide detectives to appeal to the public for help. ``They're asking for anyone who knows or may have witnessed something to come forward,'' Beverly Ford, Boston Police Department spokeswoman, said yesterday. Kyle Andrews, 36, was clinging to life when police found him face down Thursday night in the first-floor hallway of 25 Business St., a trail of blood spatter leading to his empty apartment one floor above. An hour later, he...